midterm #1 part 1

Who was Michael from the 1955 child-development study?

-- Michael was part of the third of at-risk children who showed resilience -- born prematurely with low birth weight to teenage parents -- spent first 3 weeks of his life in a hospital, separated from his mother -- by age 8, his parents were divorced, his mother had deserted the family, and he and his three brothers and sisters were being raised by their father with the help of their elderly grandparents -- by age 18, Michael was successful in school, had high self-esteem, was popular with his peers, and was a caring young man with a positive attitude toward life

how do children shape their own development?

-- child as an active participant in their own development: they shape their own development by their interests, responses (hostile attribution bias), talents (some are just more physically coordinated than others), predispositions (eg. temperament, higher or lower physical activity shown through monitors on beds reporting how much they move) -- example from lecture: Broaders' niece reacted strongly and disliked being touched while her nephew didn't mind (emotional differences); niece was more likely to want alone time and nephew was more likely to want to hang out with Broaders when she was their nanny -- example from lecture: matthew effect: age cutoff for hockey leagues (january and february born kids came into the game with slightly better reflexes, hockey-specific skills, etc. but not all january and february born kids became professional hockey players) -- example from lecture: attention span (Broaders' older son had more exposure to his grandfather and had more interest in different kinds of books because he had a higher attention span) -- children's actions contribute to their development in attention, language use, and play -- infants shape their development through selective attention. newborns attend more to objects that move and make sounds than to other objects, which helps them learn about important parts of the world (people, other animals, inanimate moving objects like vehicles). when looking at people, infants' attention is particularly drawn to faces, especially their mother's face. given a choice of looking at a stranger's face or their mother's, 1-month-olds choose to look at their mothers. at first, infants' attention to their mother's face is not accompanied by any visible emotions but by the end of the second month, infants smile and coo more when focusing intently on their mother's face than at other times, which elicits smiling and talking by the mother and subsequently elicits more cooing and smiling by the infant. infants' preference for attending to their mother's face leads to social interactions that can strengthen the mother-infant bond -- children begin to speak usually between 9 and 15 months of age -- toddlers (1- and 2-year-olds) often talk when they are alone in a room (crib speech), which only happens because children are internally motivated to learn language. crib speech probably helps toddlers learn language -- a baby banging a spoon against the tray of a high chair or intentionally dropping food on the floor is learning about the noises made by colliding objects, the speed at which objects fall, and the limits of their parents' patience -- starting at around age 2, children sometimes pretend to be different people in make-believe dramas (fantasy play), which contributes to their knowledge of themselves and other people -- play teaches children to cope with fears, resolve disputes, and interact with others. older children's play typically has more rules and organization, which fosters self-control for turn-taking, adhering to rules, and controlling one's emotions in the face of setbacks -- children's contributions to their own development strengthen and broaden as they grow older

sociocultural theories: overview

-- child shaped by tools of culture and society (child as apprentice); cognitive mediation theory; inter-mental becomes intra-mental; children's private speech (Piaget viewed it as immature while Vygotsky viewed it as being used for self-regulation and to plan, guide, and monitor behavior); social origins of cognitive development (effective social interaction: inter-subjectivity, scaffolding, guided participation); zone of proximal development is between current level and potential level and it shifts (not unitary); cooperative learning; targeted instruction -- Vygotsky & sociocultural theories: he did research before piaget but it wasn't known in the west before; child is observing people around them, and that is driving their development; taking external and internalizing it gradually to make it your own; John Locy gave children a straight piece of PCB tubing, a Y-shaped PCB tubing, and a Y-shaped stick (WEIRD/Western children are more likely to sort based on shape; children in Hichimayan community are more likely to sort based on substance); children's private speech (talking to themselves) was viewed by Piaget as egocentrism but was viewed as Vygotsky viewed it as internalizing what adults told them (example: Broaders' younger sister's mother-in-law watched the kids but never child-proofed the place. Instead, she said "No, no, no, not for Dani, don't touch." Dani is about to touch a Christmas ornament, reaching her hand out, and instead whispers, "No, no, no, not for Dani, don't touch" and puts her hand down; inter-subjectivity (we attend to the same thing and both know we are paying attention to the same thing); scaffolding (lifts you up to the level you need to be that otherwise you can't get to; adults bring the higher-level task to the level you can do it at with your skills); guided participation (gives direction from the side; may model but then lets the child do it themselves); zone of proximal development (five-year-old can add simple numbers, might be able to subtract simple numbers, but definitely can't do calculus. Zone is subtracting simple numbers) should be targeted by teachers (individualized) and keeps growing the more you learn; cooperative learning (those who are more advanced should interact with those less advanced; output produced by advanced students is in the zone of proximal development for less advanced; more advanced students learn it better when teaching it) -- kids who are about nine can't solve math equalizer problems (carry strategy, add to equal strategy (hand drop in the gesture is important), add all strategy, grouping equal atoms, equalizer strategy, add-subtract strategy; each have their own gestures but children with implicit understanding verbally use an immature strategy but their hand gestures show a mismatch with their words); those with implicit understanding are in the zone of proximal development -- approaches that emphasize that other people and the surrounding culture contribute greatly to children's development and the importance of children's interactions with others -- much of cognitive development takes place through interactions between children and other people who want to help the children acquire the skills, knowledge, beliefs, and attitudes valued by their culture -- guided participation: more knowledgable individuals organize activities in ways that allow less knowledgable people to perform the activity at a higher level than they could manage on their own. often occurs when the explicit purpose is to achieve a practice goal in which learning more general skills occurs as a by-product. important type is social scaffolding, a process through which adults and others with greater expertise organize the physical and social environment to help children learn (more competent people provide a temporary framework that supports children's thinking at a higher level than children could manage on their own). this is the way parents and teachers tend to instruct children. the more that it focuses at, but not beyond, the upper end of the child's capabilities, the greater that child's learning tends to be -- cultural tools: symbol systems, manufactured objects, skills, values, and the many other ways in which culture influences our thinking

theme #4: mechanisms of change

-- how change occurs (biologically determined, variability, input specific) -- some domains: language skills, friendship strategies, problem-solving abilities differ by age) -- domain specific (skill, mechanism, or ability that only affects a small area like mathematical reasoning; how to compose the past tense in language) vs. domain general (working memory capacity affects everything) -- biologically determined: brain development unfolds at a predictable rate (myelination on a predictable schedule; eg. effortful attention requires myelination of a specific brain area); studies of kids trying to reach into clear boxes to see if they can get the object; infants have a strong palm-and-grasp reflex (they need development in the prefrontal dorsolateral cortex to stop); infants with the reflex give up at the clear box task while kids without the reflex succeed -- effortful attention: voluntary control of one's emotions and thoughts (inhibiting impulses, focusing attention), brain activity is especially intense in connections (that develop considerably during childhood) between the limbic area (which plays a large role in emotional reactions) and the anterior cingulate and prefrontal cortex (which are involved in setting and attending to goals) -- spending one's childhood in poverty has a negative effect on the brain activity needed to suppress negative emotions and improve effortful attention many years later in adulthood -- variation in genes influencing production of key neurotransmitters are associated with variations in the quality of performance on tasks that require effortful attention and are associated with differences in how the quality of parenting affects their effortful attention -- Rueda and colleagues 2005 presented 6-year-olds with a 5-day training program that used computerized exercises to improve capacity for effortful attention. examination of electrical activity in the anterior cingulate indicated that 6-year-olds who completed the exercises showed improved effortful attention and improved performance on intelligence tests so the learning and experiences of children influence their brain processes and gene expressions (genes, brain structures and processes, and experiences interact) -- variability: first steps involve learning and variability (different paths to get to furniture to help them get up and walk: scooting backwards, rolling, crawling); kids learn to solve simple addition problems with varied strategies (eg. memorization, count upwards, use fingers, start with the bigger number) -- input specific: you will never become mozart if you are never exposed to using a piano -- study of states (when you have the skill or you don't) and transitions (movement from not having the skill to having the skill). mechanisms of changes are more apparent during transitions -- will need several mechanisms for a given skill (to be able to produce language, you need cognitive mechanisms to be able to understand symbolic representations, you need to motor mechanisms to be able to control vocal apparatus like how you shape your tongue and other forms of physical control) -- mechanisms can be behavioral, neural, or genetic (eg. mathematical development through the behavioral mechanism of improved strategies, the neural mechanism of increased interconnection between the frontal cortex and the intraparietal sulcus, and the genetic mechanism of the presence or absence of specific alleles) -- changing role of sleep in promoting learning and generalization: 6-month-olds average 14-15 hours of sleep per day. the type of learning that sleep promotes changes with the maturation of the hippocampus. during the first 18 months after birth, sleep improves learning of general, frequently encountered patterns but not learning of the specifics of material presented only once or twice. after 24 months, when tested shortly after napping, children often remember the specifics of what they learned better than peers who did not nap during that period but their memory for general patterns is no better than those of peers who did not nap (Werchan and Gómez 2014 used active systems consolidation theory that the hippocampus (specific details)n and cortex (general patterns) simultaneously encode new information during learning and that in older children and adults, hippocampal memories are replayed during sleeps which allows the cortex to extract general patterns from the specific memories stored in the hippocampus and vice versa. they said infantile sleep reflects cortex (because hippocampus is too immature to be benefited by sleep) while preschoolers' sleep reflects hippocampus.

fetal experience and behavior

-- importance to later development: physical characteristics and health, mental health, cognitive functioning -- fetal alcohol syndrome is an example of physical and health effects, influenza virus prenatal exposure increases risk of schizophrenia and maternal emotional stress in second trimester can make fetuses have a more sensitive stress response (mental health effects), how brain structures are wired together (world war II study where the dutch were blockaded and individuals whose mothers were on a restricted diet during the famine were more likely to be obese due to effects on their metabolic activity; females develop eggs prenatally so what you're grandmother ate when she was pregnant affects your likelihood of obesity) -- prenatal stages: zygote (first two weeks after conception, before implantation), embryo (implantation through 8th week, up through gestation; embryo is most vulnerable; most likely to experience miscarriage, women trying to get pregnant are encouraged to start taking prenatal vitamins early because of this), fetus (9th to 38th weeks) -- fetal sense of touch (will withdraw from a needle, suck their thumb), taste (too much amniotic fluid putting too much pressure on the fetus but the fetus will drink it and expel it through the umbilical cord if you inject sucrose into the fluid), smell (newborn infant will turn their heads toward their own amniotic-fluid-soaked cotton diaper), hearing (study of reading cat in the hat out loud, infants postnatally showed a preference for the story they heard because they recognize the cadence, pattern, intonation; exposed to mothers' heartbeat and digestive sounds that improve brain development for the infant and infants born prematurely have those sounds played for them to mimic the womb), babies are born legally blind (they have some/minimal visual processing. If you project a bright light onto the uterus, they will respond), fetal learning (habituation - if there's a new sound, they'll respond, they like hearing their mother's voice because their voice is familiar) -- although the uterus and the amniotic fluid buffer the fetus from much of the stimulation impinging on the mother, the fetus still experiences an abundance of sensory stimulation and is capable of learning and developing behaviors -- the formation of organs and muscles depends on fetal activity -- 32-week-old fetuses whose heart rates were generally slower and who moved less were more behaviorally inhibited at 10 years of age -- despite their very different environments, fetuses and children show surprising similarities -- movement: -- from 5 or 6 weeks after conception, the fetus moves spontaneously -- one of the earliest distinct patterns of movement to emerge (at around 7 weeks) is hiccups -- one theory says a reason for prenatal hiccups could be a burping reflex, preparing the fetus for eventual nursing by removing air from the stomach to make more room for milk -- swallowing is a prenatal reflex that helps to prepare the fetus for survival outside the womb. fetuses swallow amniotic fluid, most of which is excreted back out into the amniotic sac. the tongue movements associated with swallowing promote the normal development of the palate. also, the passage of amniotic fluid through the body helps the digestive system mature properly -- beginning as early as 10 weeks after conception, the fetus promotes its respiratory readiness by exercising its lungs through "fetal breathing," moving its chest wall in and out. no air is taken in. small amounts of amniotic fluid are pulled into the lungs and then expelled. fetal breathing is initially infrequent and irregular but then increases in rate and stability. by the third trimester, fetuses "breathe" roughly once per second -- touch: -- grasp their umbilical cords, rub their face, suck their thumbs (majority of fetal arm movements during the second half of pregnancy result in contact between hand and mouth. fetuses who suck their right thumb are more likely to be right-handed and vice versa) -- as it grows larger, it bumps against the walls of the uterus more often -- by full term, fetal heart rate responds to maternal movements, suggesting that their vestibular systems (sensory apparatus in the inner ear that provides information about movement and balance) is also functioning before birth -- sight: -- not totally dark inside the womb -- fetuses can process visual information by the third trimester of pregnancy and like newborn infants, fetuses have visual preferences (recent study: 4-D ultrasound measured what third-trimester fetuses preferred to look at by projecting light patterns onto pregnant women's abdomens. fetuses preferred light displays that are top-heavy and resemble correctly oriented faces over those that are bottom heavy and resemble inverted faces. infants' predispositions to look toward face-like stimuli may not require postnatal experience -- taste: -- study preformed more than 60 years ago: a physician, DeSnoo 1937 came up with a treatment for women with excessive amounts of amniotic fluid. he injected saccharin into the fluid, hoping the fetus would help the mother by ingesting increased amounts of the sweetened fluid, diminishing the excess. tests of the mother's urine showed that the fetuses ingested more amniotic fluid when it had been sweetened -- smell: -- amniotic fluid takes on odors from what the mother has eaten and comes into contact with fetus's odor receptors through fetal breathing -- phylogenetic continuity: because of our common evolutionary history, humans share many characteristics, behaviors, and developmental processes with non-human animals, especially mammals -- rat birth process: nipples on the underside of the mother rat's belly are smeared with amniotic fluid and its scent is familiar to the rat pups from their time in the womb, which lures the babies to the mother's nipples for nursing. when the mother rat's nipples are washed immediately after birth, newborn rats fail to attach to her nipples -- hearing: -- surprisingly noisy prenatal environment dominated by mother's heartbeat, blood flow, and breathing -- from the fetuses' vantage point, digestive sounds occur roughly 5 times per second. the noise level in the uterus ranges from about 70-95 decibels. mother's voice is particularly prominent (fetus heart rate changes when the mother starts speaking) -- during the last trimester, external noises elicit changes in fetal movement and heart rate as well (fetal heart rate increases when recordings of the mother's or father's voices are played near the pregnant mother's abdomen. fetuses can distinguish between music and speech played near the mother's abdomen) -- uterine auditory experience: Webb and colleagues 2015 studied a group of hospitalized preterm infants who spent several hours each day listening to recordings of their mothers' uterine sounds (voices and heartbeats). at 1 month of age, their brain development was compared to another group of preterm infants exposed only to regular hospital sounds. preterm infants exposed to womb sounds had larger auditory cortexes than the control group

how do nature and nurture together shape development?

-- nature refers to biological endowment (genes we receive from our parents; genetics/biology) -- nurture refers to the wide range of physical and social environments that influence our development (environment) -- longest standing debate (socrates said all knowledge is already present, thought we come into the world preloaded with all the human software we need and we just need to find a way to access the information we already know, example: he's at a dinner party and asked questions of a slave to get him to provide a geometric proof without any formal mathematical training; Aristotle said we are a product of our experience and is an empiricist, said we are constantly learning from the world around us, thought that women had fewer teeth than men, thought that mice would die if they drank water in the summer, thought flies came out of rotting meat, basically, he didn't test out his theories; Locke's phrase was tabula rasa and discipline is needed, was a hardcore empiricist; Rousseau said children need freedom and that humans are noble savages, said we have a fundamentally positive nature that gets corrupted and we shouldn't get in the way if we want good child development -- not a dichotomy (always the relative contribution of both) -- examples from lecture: -- Broaders can't just plant random seeds in certain areas to get kale or tomatoes (you need to buy kale seeds and tomato seeds - fundamental biological component). If they sprout and how healthy they are when the sprout is due to environmental factors (they grow into better or worse states of themselves based on the environment) -- gilbert gottleib's duckling imprinting studies; ducklings imprint on adults; some other types of birds imprint by sound (they imprint on the first thing they hear make an adult quacking sound); self-produced sounds in the egg before they hatch (sounds nothing like a hatch); gottleib did surgery through the egg to cut their vocal cords so they can't make sounds anymore and the lack of that self-produced sound resulted in them not imprinting on adults based on the quacking -- prenatal development: epigenetic factors, fetal alcohol syndrome -- Hebb (1980) said behavior is determined 100% by heredity and 100% by environment -- all human characteristics are created through the joint workings of and bidirectional interactions between nature and nurture -- right question to ask because of findings on the development of schizophrenia (high genetic loading: if one twin has schizophrenia, the other has 40-50% chance of also having schizophrenia as opposed to the roughly 1% probability for the general population. children who grow up in troubled homes are more likely to become schizophrenic) -- a study of adopted children indicated that the only children who had any substantial likelihood of becoming schizophrenic were those who had a schizophrenic parent and who also were adopted into a troubled family -- recent series of studies show that genomes influence behaviors and experiences, which in turn influence the genome. proteins that regulate gene expression by turning gene activity on and off change in response to experience and can produce enduring changes in cognition, emotion, and behavior. -- these studies gave rise to epigenetics, which is evidenced by methylation (biochemical process that reduces expression of a variety of genes and is involved in regulating reactions to stress). one study showed that the amount of stress that mothers reported experiencing during their children's infancy was related to the amount of methylation in the children's genomes 15 years later. other studies showed increased methylation in the cord-blood DNA of newborns of depressed mothers and in adults who were abused as children, leading researchers to speculate that such children are at heightened risk for depression as adults

Piaget's theory of cognitive development (central development issues)

-- nature and nurture interact to produce cognitive development. main sources of continuity are assimilation (people incorporate incoming information into concepts they already understand), accommodation (people improve their current understanding in response to new experiences), and equilibration (people balance assimilation and accommodation to create stable understanding in three steps: first, equilibrium where people are satisfied with their understanding. then, disequilibrium from a realization that their understanding is inadequate because of new information. finally, a more advanced equilibrium after the development of a more sophisticated understanding that eliminates at least some of the shortcomings of the old one) -- constructivist approach: children discover knowledge through their own activity, engage in meaning-making behaviors -- two basic methods: assimilation (encounter a new situation and use your current scheme with it; using current schemes to interpret external world) and accommodation (refine your scheme to the new situation when it doesn't perfectly match; adjusting old schemes and creating new ones to better fit environment) -- equilibration: keep refining your scheme until it matches the world; back-and-forth adjustment -- organization: internal rearranging and linking schemes -- where do mental representations come from and how do we change them over time, internal depiction of information and images/concepts for mental representations -- we want adaptation to accurately reflect the world and help us function in it (adaptation responds to demands of environment, aims to meet own goals, building and adjusting schemes) -- schemes: organized way of making sense of experience, changes with age, mental organizations of information (internal mental constructs) that gradually change our understanding of the world (creation and refinement) -- most famous part of theory was discontinuity part -- stages: sequential levels of adapting -- stage theory: you have to master the challenges at one stage before you can move into the next stage (hierarchical), invariant (no matter who or where you are), method was looking at how children performed when induced to (what mental structures would account for the observed behavior?); they use assimilation, accommodation, and equilibration; discrete -- sensorimotor, preoperational (sometimes goes to age 8), concrete operational, formal operational -- central properties of stage theory: qualitative change (example: children in the early stages of cognitive development conceive of morality in terms of the consequences of behavior while children in later stages conceive of it in terms of intent), broad applicability (characteristic type of thinking influences children's thinking across diverse topics), brief transitions (fluctuate between two types of characteristic thinking), invariant sequence (everyone progresses through the stages in the same order without skipping any of them -- domain general, invariant, universal, method (induce underlying cognitive structures for behavior) -- children of a given age use particular strategies to solve a particular class of problems: 5-year-olds solve conservation-of-number problems by choosing the longer row of objects. 7-year-olds solve the same problems by reasoning that if nothing was added or subtracted, the number of objects must remain the same

Piaget's theory of cognitive development (from overview)

-- piaget overview: founded the field of cognitive development, background in biology and philosophy, wrote a paper on mollusks when he was only 18 (really good at observing and describing); when helping with the standardization of IQ tests, he turned his attention to humans (helped collect data for Binet; became interested in why children had incorrect/non-standard answers for questions; wide set of research methods (baby biographies of their children, simple experiments with his kids like hiding his daughter's toy to see what she would do, designed standardized tasks to measure students' condition like conservation-of-number, naturalistic observation of a playground for his theory of moral development), mental embryology -- before Swiss psychologist Jean Piaget's work (early 1920s), there was no recognizable field of cognitive development -- best-known cognitive developmental theory -- cognitive development involves a sequence of four stages: sensorimotor, pre operational, concrete operational, and formal operational. they are constructed through assimilation, accommodation, and equilibrium -- reasons for longevity: vividly conveys textures of children's thinking at different ages, offers an intuitively plausible depiction of the interaction of nature and nurture in cognitive development and the continuities and discontinuities that characterize intellectual growth, and extends from infancy through adolescence and examines topics such as conceptualization of time, space, distance, and number; language use; memory; understanding of other people's perspectives; problem solving; and scientific reasoning -- removing an object from a young infant's sight (younger than 8 months) should lead the infant to act as if the object never existed (this was based on Piaget's informal experiments with infants younger than 8 months. he would cover one of their favorite playthings with a cloth or otherwise put it out of sight and then wait to see whether the infants tried to retrieve the object. they rarely did, leading Piaget to conclude his theory about infant reactions to disappearing objects). other researchers argue that infants younger than 8 months do understand that hidden objects continue to exist but lack the memory or problem-solving skills necessary for using that understanding to retrieve hidden objects. Yuko Munakata and her colleagues 1997 tested whether 7-month-olds' failure to reach for hidden objects was due to their lacking the motivation or the reaching skill to retrieve them. the researchers created a situation similar to Piaget's object-permanence experiment, except they placed the attractive toy under a transparent cover. infants quickly removed the cover and regained the toy. in contrast, an experiment conducted by Adele Diamond 1985 used an opaque covering and varied the amount of time between when the toy was hidden and when the infant was allowed to reach for it. even 6-month-olds could locate the toy if allowed to reach immediately, 7-month-olds could wait as long as 2 seconds and succeed, and 8-month-olds could wait as long as 4 seconds and succeed. memory for the location and the understanding that they continue to exist are both crucial to successful retrieval

what is meta-analysis?

a method for combining and analyzing the results from several independent studies

a team of researchers is studying whether stable individual differences exist in sleeping behavior at various ages. they decide to test 3-month-olds, 6-month-olds, and 9-month-olds. what type of design are they using to examine this question?

cross-sectional

sociocultural theorists emphasize the child's

direct interactions with others

Although Piaget argues that infants younger than 8 months fail the A-not-B error test due to a lack of object permanence, proponents of dynamic-systems theories argue their failure is

due to a combination of habit, memory demands, and focus of attention

core-knowledge theories argue that ________ plays a role in cognitive development

evolution

information-processing theories note several limits on children's thinking. which of the following is not one of these limits?

implementation of task analysis

the experience that children in an experimental group receive and which children in a control group do not receive is referred to as the _______

independent variable

the process of synaptogenesis

involves the formation of connections between neurons

a noted accomplishment during Piaget's sensorimotor stage is

object permanence

ontogenic adaptations vs. deferred adaptations

ontogenic: some aspects of developmental immaturity have been selected for their adaptive value for individuals at a specific time in development deferred: some aspects of developmental immaturity have been selected for their adaptive value for individuals as preparation for adulthood

Marcus has red hair, green eyes, and freckles. He is very active but shy. These characteristics are a reflection of Marcus's

phenotype

the capacity of the brain to be modeled or changed by experience is referred to as

plasticity

according to Vygotsky's sociocultural theory, young children will often talk aloud to themselves as a means of controlling their behavior. this is referred to as _______ speech

private

what changes in cognitive development? (lecture slides)

processing capacity, processing efficiency/working memory, encoding and representation/attention, knowledge, strategy execution, strategy selection and regulation, interaction of dimensions

The continual switching on or off of specific genes at specific times throughout development is the result of a chain of genetic events primarily controlled by

regulator genes

what is the study of developmental psychology?

scientific approach to study of constancy and change across the lifespan (from conception to adolescence) -- focus on "normal" development

the points at which neurons communicate with one another are called

synapses

By administering the same test to the same group of participants under similar conditions two or more times, a researcher can measure ___________ reliability.

test-retest

the turtle shell technique is an example of a successful intervention that helps preschoolers cope with _____

their own anger

what is not a symptom of fetal alcohol syndrome?

underactivity

overlapping waves theory explains children's ability to

discover new strategies that lead to more efficient problem solving

seven questions/themes that are the basis for the modern study of child development

1. how do nature and nurture together shape development? (nature and nurture) 2. how do children shape their own development? (the active child) 3. in what ways is development continuous, and in what ways is it discontinuous? (continuity/discontinuity) 4. how does change occur? (mechanisms of change) 5. how does the sociocultural context influence development? (the sociocultural context) 6. how do children become so different from one another? (individual differences) 7. how can research promote children's well-being? (research and children's welfare)

core-knowledge theories

-- infants begin life with innate special-purpose knowledge systems; relevant to tasks evolutionary importance; nativist version (born with substantial knowledge of important domains, core domains of thought are: physical, numerical, linguistic, spatial, psychological); constructivist version (specialized learning abilities, children create theories of the world and test them) -- core-knowledge: current nativists, what seems to be built as a function of having a human mind, if the mind is a product of evolution, it makes sense that evolutionary pressures would create hard-wired defaults that are important; infants are surprised if you drop the screen and only one object is behind it, the conceptually impossible scene -- nativist version (like socrates, but not as far): two solid objects can't pass through each other (physical knowledge), being able to hear speech and be able to use it (linguistic), rudimentary spatial placement (spatial), humans have feelings but objects don't; person reaches for the teddy bear 8 times and then swap the objects so that person reaches for the ball (infants are surprised that the person wants the ball too; they understand human intentions and don't care if a fake arm like a rod reaches in both scenarios as the human arm) - constructivist: specialized learning mechanisms like fast association of one concept with another; quickly adding to domains of evolutionary importance -- when placed in a situation where they are likely to transgress, the percentage of children who lie about it steadily increases from age 2 to age 7, presumably due to increasing ability to imagine potential tells and generate ways of avoiding them -- core-knowledge theories: approaches that view children as having some innate knowledge in domains of special evolutionary importance and domain-specific learning mechanisms for rapidly and effortlessly acquiring additional information in those domains -- two characteristics reflected by deception studies: studies focus on types of knowledge that have been important throughout human evolution and the assumption that in certain areas of probable importance in human evolution, infants and young children think in ways that are considerably more advanced that Piaget suggested were possible (if preschoolers were completely egocentric, they wouldn't lie because they would think the others' knowledge is the same as their own -- view of children's nature: children as active learners and well-adapted products of evolution (3-year-olds understand deception much better when they are actively involved in perpetrating the deceit than when they merely witness the same deception being perpetrated by others), differ dramatically from piagetian and information-processing theories in their view of children's innate capabilities (view children as entering the world with specialized learning mechanisms or mental structures that allow them to quickly and effortlessly acquire evolutionarily important information). proposed domain-specific understandings (children distinguish between living and nonliving things, anticipate inanimate objects to remain stationary unless an external force is applied, anticipate that animals might well move on their own) with different mechanisms that produce them (eg. a theory of mind module mechanism is believed to produce learning about one's own and other people's minds) -- central developmental issue: disagreement over how much knowledge is inborn. nativists (emphasize innate knowledge; most prominent theory, labeled core-knowledge theory, proposed by Elizabeth spelke who hypothesized that infants begin life with four core-knowledge systems that have their own principles. one represents inanimate objects and their mechanical interactions, second represents the minds of people and other animals capable of goal-directed actions, third represents numbers, and fourth represents spatial layouts and geometric relations. numerous studies have documented that infants know that all objects occupy space, move in continuous ways through it, and cannot simultaneously occupy the same space as another object. children have the language acquisition device which allows them to rapidly master the complicated systems of grammatical rules present in all human languages and those of their native language without direct instruction from adults. universality of acquisitions early in life, without apparent effort, and without instruction from other people, is characteristic) and constructivists (emphasize the generation of increasingly sophisticated domain-specific theories through subsequent experience on top of the innate foundation. infants' initial knowledge in domains of evolutionary importance is rudimentary and construction of more advanced knowledge reflects specific learning experiences within the domain. proposed that young children organize understanding into informal, naive theories of physics, psychology, and biology by identifying fundamental categories, explaining phenomena with a few principles, and explaining events in terms of unobservable causes. children's initial theories grow more complex with age and experience. Henry Wellman and Susan Gilman 1998 suggested that the first theory of psychology emerges at 18 months and is organized around the understanding that other people's actions reflect their own goals and desires. 2-year-olds realize that another person will want to eat if they are hungry regardless of whether the children themselves are hungry. first theory of biology emerges at 3 years and is organized around the realization that people and other animals are living things, different from nonliving things. 3- and 4-year-olds realize that people and animals, but not inanimate objects, can heal themselves. by age 7, children believe "living things" also includes plants. by age 3 or 4, children recognize the role of beliefs in influencing people's actions) -- educational applications: young children are essentialists (members of a species have a fixed inner essence making them what they are), which interferes with learning about natural selection. Deborah Kelemen and her colleagues 2014 helped 5- to 8-year-olds learn about natural selection with storybooks about fictitious animals called pilosas who were suddenly dying off due to extreme climate change that caused the insects they ate to burrow further underground. some pilosas had thin trunks that allowed them to reach into the narrow burrows and survive to reproduce but others had trunks too wide and starved before they could reproduce. the children could generalize natural selection to a different hypothetical species. consistent with core-knowledge theories, storybooks with more information about causal mechanisms led to greater learning

Although 15-month-old Lena has been walking unassisted for several months, on recent trips to the park her father has noticed Lena walking on some areas of the playground but crawling on others. Lena's regression from walking to crawling in this example is best explained by which theory?

overlapping waves theory

secret life of the brain, episode 1

-- a baby's brain is less than one pound of gelatinous tissue -- Elizabeth traphagan: born at 28 weeks and 6 days (3 months early) at Brigham Women's Hospital in Boston, weighed 3 pounds and was 14 inches long. -- egg and sperm divide themselves again and again into a cluster of cells that becomes the neural tube (bottom is spinal cord, top is brain). neurons leave the inside of the neural top to make up the brain, layer by layer. each neuron goes by itself and uses glial cells -- by 4 weeks of pregnancy, the first neurons are forming, 500,000 neurons per minute -- stanford neurologist susan mcconell: tracks the destiny of a migrating neuron. took stem cells that were about to become neurons and implanted them into developing brains. they went to the same location as the neighbor cells. but when she transplanted neurons, they went to a different location than the neighboring cells; the one they were meant to go to -- by 24 weeks, the vital organs of the fetus are well-formed. the heart can beat on its own. lungs are prepared to breathe air -- strategy of neural system to make correct synaptic connections is in the genes. first phase of wiring is genetically determined and many neurons are making incorrect connections. second phase is "use it or lose it" (incorrect connections are gotten rid of because they are not being strengthened and reinforced) -- developmental psychologist Heidelise Als: glare and clamor of intensive unit is part of the problem for premature babies. studying Elizabeth and other premature babies for the next 8 years. EEGs will record her brain impulses while MRIs will reveal her brain's hidden structures. Als designed the intensive unit Elizabeth is in that is quiet and slow and has the baby stay with the mother (skin to skin contact). Elizabeth was strong enough to go home at 6 weeks old. she was checked by Als 3 weeks after she was supposed to have been born and Als will compare her brain development to that of premature babies who had a typical intensive care unit experience. the toy Als used really captured Elizabeth's attention. she did a good job of shutting out the light with just a little adjustment in breathing first. she's symmetrical, strong, and came to alertness in terms of physical strength and reflexes. Elizabeth's MRI showed normal brain maturation and her EEG showed a normal, full term brain EEG -- nearly half of premature babies will have difficulty paying attention, learning, planning, imposing structure, prioritizing -- fetuses don't have to breathe on their own in the womb (mother's body takes care of it) -- when you're holding a baby and peering down at it, your face is at the location babies' most like to look at. by two days of age, a baby can recognize its mother by sight alone. researchers think what a newborn baby sees looks like a faded photograph. the eye dampens down the stimulation because the brain can't yet handle it (but it needs some visual stimulation still) -- Holly McMillan has a cataract over her right eye that needs to be removed ASAP. even just one or two months of missing visual stimulation after birth can have permanent consequences on the brain. within a week of the operation, holly's eye is healed and dr. levin inserts a contact lens which holly will need for the rest of her life. for at least 5 years until her visual development stabilizes, she will have to wear a patch over her left eye or else her brain will never use her right eye to see. within 10 minutes of first being able to see after cataract removal and contact insertion, the baby can see as well as a newborn (but not as well as babies their own age). within an hour, they see significant improvement (faster than regular development) -- Dr. Lewis: cataract babies' vision continues to improve until their 1st birthday (though, they start falling behind after). still, the eye can end up functioning good and healthily. 7 months after the cataract removal for holly, and she has improved

the newborn infant: state of arousal

-- a continuum of arousal, ranging from deep sleep to intense activity -- Western babies tend to spend 8 hrs in quiet sleep, 8 hrs in active sleep, 1 hr in drowsing state, 2.5 hrs in alert-awake state, 2.5 hrs in active-awake state, and 2 hrs in crying state -- sleep: average newborns sleep twice as much as young adults do, and the pattern of REM (rapid eye movement; active sleep state associated with dreaming in adults; characterized by quick, jerky eye movements under closed lids, a distinctive pattern of brain activity, body movements, and irregular heart rate and breathing) sleep and non-REM (quiet sleep state; characterized by the absence of motor activity or eye movements and more regular, slow brain waves, breathing, and heart rate) sleep changes dramatically with age: REM sleep constitutes 50% of a newborn's total sleep time, and that proportion declines quite rapidly to only 20% by 3 or 4 years of age and remains low for the rest of life. possibly helps develop the infant's visual system: high level of internally generated brain activity that occurs during REM sleep may help to make up for the natural deprivation of visual stimulation, facilitating the early development of the visual system in both fetus and newborn. natural jerking movements (myoclonic twitching) may give infants opportunities to build sensorimotor maps. twitching movements are most frequent during early development and may help the infant with the difficult problem of linking motor patterns with the specific sensations they evoke. neonates' slumbering brains do not become disconnected from external stimulation to the same extent that the brains of older individuals do so newborns can learn during sleep. one study exposed infants to recordings of foreign vowel sounds while they slept in the newborn nursery, and when tested in the morning, their brain activity revealed that they recognized those sounds. newborns gradually develop the more mature pattern of sleeping through the night, and nighttime awakenings typically diminish over the course of the first postnatal year. 1/3 of parents of 6-month-old children in the US report that their infants continued to wake up at least once every night, and even by 12 months of age, only about half of the infants in a Canadian study slept for at least 8 hours at a stretch. study said infants in a graduated-extinction group (parents slowly increased their delays in responding to their crying infant) showed greater improvement in sleep behaviors with no negative effects on infant stress (cortisol levels) or infant-mother attachment. also, bedtime fading (in which the bedtime is shifted later to ensure sleepiness and then gradually moved earlier) had success (large decreases in nocturnal wakefulness and positive effects on maternal stress). in rural Kenya, Kipsigis babies are almost always with their mothers (during the day, they are carried on her back, and at night, they sleep with her and are allowed to nurse whenever they awaken) -- crying: crying increases over the first few months (peaking around 6 to 8 weeks of age), then decreases around 3 to 4 months of age (bouts tend to increase in the late afternoon and evening). shaken baby syndrome can result in severe head trauma or death (parents concerned about incessant crying may shake their baby). many effective soothing techniques involve moderately intense and continuous or repetitive stimulation. one common technique is swaddling, which restricts limb movement while providing a constant high level of tactile stimulation and warmth (practiced by the Navajo and Hopi, the Quechua, and Turkey rural villagers). Bell and Ainsworth 1972 found that prompt responding to infant cries predicted less crying several months later. Hubbard and van Ijenzdoorn 1991 found that ignoring cries during the first 9 weeks caused infants to cry less during the next 9 weeks. mothers in rural Fiji are more likely to rapidly respond to their infant's negative facial displays of affect than US urban mothers. regardless of soothing, some infants excessively, inconsolably cry for no apparent reason during the first few months, which is called colic. causes may include allergic responses to the mother's diet, formula intolerance, immature gut development, and/or excessive gassiness. more than 1 in 10 US infants suffer from it, but it typically ends by about 3 months of age and has no longterm effects

Piaget's stages of cognitive development: sensorimotor stage

-- cheat sheet: not symbolic, not logical, not abstract -- sensorimotor stage (birth to 2): language/talking is an important transition from infancy to childhood, piaget said children come into the world with reflexes and ability to make physical actions (only building schemes and assimilating and accommodating through these), circular reactions (doing the same thing again; piaget divided them into 6 substages with gradual progression of how much intention and an expansion of domains in which they're happening: 1) reflexes like palm-thumb grasp or foot kicking if you hit the nerve, 2) "wait that was a cool movement. let me do it again," 3) "let me try it again on a different object"), object permanence (did not understand that objects continue to exist if they stopped seeing them in an "out of sight, out of mind" concept, but eventually they understand how to find the hidden object; A-not-B search error is that there are two different hiding locations and they keep looking in the first location even though they watched you change the hiding location; invisible displacement: as the child watches, A and B locations are transformed and they understand the moved hiding locations took the object with it), deferred imitation (copying an observed behavior days later, recognize stimulus and how someone interacted with it), make-believe play (if the child can pretend a block is a truck, they must have some sort of mental representation of a truck to be able to assimilate the block into it) -- building schemes through sensorimotor action patterns, circular reactions, sensorimotor development (repeating chance behaviors, intentional behavior, object permanence), development of object concept (out of sight, out of mind; hidden objects; A-not-B search error, invisible displacement, full object concept), mental representation evidence (deferred limitation and make-believe play) - for A-not-B search task, you normally hide it at the first location at least three times for more entrenched understanding - example: a video of a 12-month-old baby shows they understand the object is there when hidden, does not make the A-not-B search error (we don't know if he understands invisible displacement because the first time the locations were moved, he was rubbing his eyes and he got bored with the game the next time and lifted both blankets up) - stages are invariant so if a baby can't succeed at the A-not-B search task, they won't be able to succeed at the invisible displacement task -- birth to age 2 years, infants' intelligence is expressed through their sensory and motor abilities, which they use to perceive and explore the world around them. these abilities allow them to learn about objects and people and to construct rudimentary forms of fundamental concepts such as time, space, and causality. infants live largely in the here and now -- sucking (gain not only pleasure but also knowledge about the world beyond their bodies), flailing, and grasping are not random behaviors but instead reflect an early type of intelligence involving sensory (perceptual) and motor activity (provide examples of active child theme) -- large amount of change in sensorimotor intelligence -- tripling of brain weight between birth and age 3 -- when objects move in front of infants' eyes, they visually track them; when they are placed in their mouths, they suck them; when they come into contact with their hands, they grasp them; when they hear noises, they turn toward them -- even during the first month, they adapt their reflexes (at birth, they suck in a similar way regardless of what they are sucking, but within a few weeks, they adjust their sucking according to the object in their mouth) -- over the first few months, infants being to organize separate reflexes into larger behavior, most of them centered on their own bodies (instead of being limited to exercising grasping and sucking reflexes separately, they can grasp an object that touches their palm, bring it to their mouth, and suck on it) -- in the middle of their first year, they become increasingly interested in the world around them (repetition of actions that produce pleasurable or interesting results like repeatedly banging a rattle) -- infants late in their first year have object permanence and search for objects that have disappeared from sight (still fragile object representations) -- A-not-B error: once 8- to 12-month-olds have reached for and found a hidden object several times in location A, they tend to reach there again even when they have observed the object being hidden in location B and are prevented from immediately reaching for it. not until around their 1st birthday do infants consistently search first at the object's current location -- at around 1 year, infants begin to actively and avidly explore how objects can be used (child as scientist; Laurent example) -- from ages 18 to 24 months, infants become able to form enduring mental representations. first sign is deferred imitation (repetition of other people's behavior minutes, hours, or even days after it occurred; example: Piaget's daughter say a playmate stamp his feet during a tantrum and then did the same thing a day later for the first time) -- early goals are concrete while later goals are often more abstract -- example: infants learn what does look like and what petting them feels like

information-processing theories: central developmental issues

-- continuous cognitive changes; examine nature and nurture work together; describe how cognitive change occurs (not stage behavior); task analysis; study development (learning, attention, memory, problem-solving skills); what changes: working memory (capacity and efficiency), parallel vs. serial processing, processing speed has individual differences, balance of strategies, use of analogies, growing knowledge of the world, implicit to explicit availability; three things that are changing are processes (for memory: event association, recognizing objects as familiar, generalizing between instances, encoding represents features of objects and events in memory and depends on prior knowledge/experience, retrieval based on recognition, recall, reconstruction, and fuzzy-trace theory; speed increases greatly throughout childhood and depends on past experiences and myelination), strategies (for memory, emerges between 5 and 8 years; selective attention is the focusing on information relevant to current goal and is related to the myelination of the reticular formation; rehearsal with 3-4 years old doing it rarely, 7-10 year olds doing it more efficiently, and over 12 years old making rehearsal clusters; organization with semantic organization beginning at 9-10 years; elaboration not happening until adolescence; meta memory developing at 4-12 years old; problems: production deficiency and utilization deficiency with children expending more mental energy for new strategies than well-learned ones), and content knowledge (scripts, knowledge about usual sequences of everyday events, begin at age 2 and become more detailed and solidified as the child ages -- cognitive variability: mechanism of change that occurs as various strategies are tried; overlapping waves is not always a shift in probabilities to using the most effective strategies; children's performance is highly variable across similar tasks, across days, across children of the same age, and even in the same day over time -- memory: multistore model (sensory is raw sensory input, short-term processes and holds information for seconds, long-term is vast and relatively permanent), executive control processes and metacognition (plan and monitor action on input), knowledge base (what children know about the world) -- information-processing theories: vast majority of theorists fall here; looking at environmental input's shaping; task analysis (behaviorists used reductionism - breaking down complex tasks into simple components; present children with a stimulus and see how they break the tasks down; gradual refinement); evidence: working memory (mental blackboard; how many pieces of information you can juggle and how well you can use those pieces both improve over time); parallel processing is when two things are happening simultaneously (eg. vision); serial processing is when things happen after each other (hearing; linear input); standard IQ has a processing speed sub-score; while learning simple addition, you might use your fingers and count upwards, start with the bigger number, memorize and just know it (different strategies that get balanced); hand-gesture strategies for math equalizer problems are implicit and get transferred to explicit -- memory: three-store model; short-term store/working memory (for mid-adolescence through adulthood, 7 +/- 2 items can be held in short-term memory for about 20-30 seconds; digit span task; most people's reverse digit span is one to two digits shorter); short-term capacity for children is 2 digits; phonological loop is more about time than number (eg. Welsh adult digit span is 5; Mandarin digit span is 9); by the time you're 30, your cognition starts to slow down; executive control (do you realize you've totally forgotten a piece of information or do you think you remember it perfectly?); content knowledge is how you're building your knowledge based on prior experiences; encoding is making meaning of various stimuli (active process); recognition is easier than recall (children and adults do better at recognition; different recall cues across ages); memory is an active constructive process (not necessarily accurate); fuzzy-trace theory (don't remember individual details but instead remember the take-home message); more entrenched connections are easier to use (one reason for faster basic processing); neural signals get where they need to get more quickly due to myelination; selective attention is partially dependent on past experience (kindergarteners remembered a fire drill as getting to go outside twice in one day instead of the fire drill) -- information-processing theories: how easy it is for you to use a strategy (how easy to find it in the moment), rehearsal is not an obvious strategy to 3-4 year olds, grouping items to rehearse them for memory starts at 12 years old, organization is linking things and putting them together by meaning for recall, elaboration is tying things in to things that you already know, metamemory is the ability to recognize that you didn't remember something the way you should/your memory of something is flawed, example: kids don't know that they're being filmed for a TV show and they had problems with encoding and with coming up with a memory strategy and/or with using a strategy like rehearsal, little kids pick their area of expertise, content knowledge effect is that what you know about the world affects what you can learn about the world -- emphasis on precise descriptions of change mechanisms -- memory systems: working, long-term, and executive functioning (control behavior and thought process, prefrontal cortex plays an important role, three key executive functions are inhibition like resisting temptation, enhancement of working memory through use of strategies, and cognitive flexibility such as imagining the other perspective while in an argument. lets the individual respond appropriately rather than acting impulsively or out of habit. increases greatly during the preschool and early elementary school years. one improvement is increased flexibility in shifting goals. when 3-year-olds are asked to sort toys by color, then sort by shape, then sort by color again, they have difficulty. 5-year-olds do this easily. example of inhibition: Simon says (which is hard for preschoolers but easier for early elementary school children). quality of executive function in early childhood predicts high school academic achievement, college enrollment, adult income and occupational prestige, and more learning from instruction intended to help them gain other skills -- explanations of memory development: basic processes (associating events with one another, recognizing objects as familiar, recalling facts and procedures, and generalizing from one instance to another. encoding is key to all other basic processes and is the representation in memory of specific features of objects and events that draw attention or are considered important. most 5-year-olds predict the side of the scale with more weight will go down regardless of its distance from the fulcrum because they don't encode the distance), strategies (between ages 5 and 8, one strategy that is used is rehearsal. preschoolers and early elementary school students use selective attention, which is intentionally focusing on the information that is most relevant to the current goal. if 7- and 8-year-olds are shown objects from two different categories and are told they will only need to remember one category later, they focus their attention on that category while 4-year-olds would still pay equal attention to both categories), and content knowledge (improves recall of new material because it is easier to integrate the new material with existing understanding. when children know more than adults about a topic, they often remember more new information about the topic than adults do. prior content knowledge helps through improving encoding. child chess experts remember chess-piece arrangements better than adult novices. prior content knowledge provides useful associations and indicates what is and is not possible -- processing speed increases the most in younger years. myelination and increased connectivity among brain regions leads to faster processing speed

hazards to prenatal development (maternal factors)

-- spontaneous abortion/miscarriage (most occur before the woman even knows she is pregnant). majority of embryos miscarried very early have severe defects (eg. missing chromosome or extra one) that make further development impossible. in the US, 15% of pregnancies end in miscarriage. in rural Kenya, 18.9%. at least 25% and possibly as many as 50% of women experience at least one miscarriage. 1% of women experience recurrent miscarriages (loss of three or more consecutive pregnancies) -- maternal age: infants born to girls 15 years or younger are 2 to 4 Tims more likely to die before year 1. risk of negative outcomes for both mother and fetus increase with maternal age (children are at heightened risk for developmental disorders like autism) -- nutrition: women who get too little folic acid (a form of B vitamin) are at high risk for having an infant with a neural tube defect such as spina bifida. -- disease: if contracted early in pregnancy, rubella (3-day measles) can cause major malformations, deafness, blindness, and intellectual disabilities. cytomegalovirus (CMV), a type of herpes, is the most common cause of congenital infection (affecting 1-5% of births) and can damage the fetus's central nervous system and cause a variety of other serious defects like hearing loss. if the infant comes into contact with active genital herpes lesions in the birth canal, blindness or even death can result. breast milk contains a carbohydrate that may actually protect infants from HIV infection. Zika, a mosquito-borne viral infection, can cause microcephaly, a condition in which the baby's head is much smaller than expected. issues can range from hearing and vision loss to seizures and intellectual disability. microcephaly occurs in 6% of fetuses whose mothers were infected by Zika; higher rates are observed for women whose Zika infections occurred during the first trimester. the virus appears to infect fetuses' cortical-neural progenitor cells, resulting in stunted brain growth -- emotional state: both structural and functional effects on the developing brain of the fetus (alterations in the hypothalamic-pituitary-adrenal (HPA) axis and the hormone cortisol, a glucocorticoid that helps regulate stress in both the mother and the fetus. long-term changes in how children and adults cope with stress via disrupted HPA axis functioning. minority ethnic pregnant people report greater rates of prenatal stress. pregnant people in less wealthy countries report even greater levels of stress. IVF study had mothers who were either genetically related or unrelated to their fetuses (effects of maternal stress were on birth weight and later antisocial behavior regardless of maternal relation so the prenatal environment instead of shared genetics was the strongest predictor. however, postnatal maternal stress was the strongest predictor for child anxiety) -- paternal age matters and older paternal age is a risk factor for schizophrenia (sperm ages even though sperm is continuously generated) -- more exercise is better than less exercise; maternal nutrition; timing of stress matters (late-second or early third trimester), under the age of 15 is a risk factor and over the age of 35 is a geriatric pregnancy, more likelihood of down syndrome the older the mother is at pregnancy -- fetal programming: belated emergence of effects of prenatal experience that program the physiological set points that will govern physiology in adulthood (inadequate prenatal nutrition: fetus's metabolism adjusts to the level of nutritional deficiency experienced in the womb and does not reset itself after birth. in a postnatal environment with abundant food, this sets the stage for the development of overweight and obesity issues) -- Netherlands in 1944 (during World War II) during the Dutch Hunger Winter. study of malnutrition independent of socioeconomic status because everyone suffered extreme famine. German occupation limited rations to as little as 400 to 800 calories per day. women in the earlier stages of pregnancy during the famine had babies of normal birth weights. however, these infants grow up to have high rates of obesity. the fetuses' metabolisms were set prenatally while they were experiencing undernutrition and were not reset when nutrition reached normal levels. in late middle age, the individuals showed impaired performance on attentional tasks and had prematurely aged brains

according to core-knowledge theorists, children possess naive theories in what three major domains?

biology, physics, and psychology

prolonged period of immaturity

-- 15 years for humans -- childhood (the 3 to 7 years between infancy and juvenile periods) and adolescence (the 2 to 3 years after the first instance of menstruation/menarche) are two newly invented life stages -- childhood extends required parental investment (cannot acquire food themselves, have limited physical abilities, egocentric, illogical in thinking) -- caring for dependent children limits the number of offspring one can have and being dependent leads to susceptibility to predation, starvation, and disease. the delayed sexual maturity increases the risk one will die before reproducing -- these drawbacks mean immaturity must have its benefits to avoid being selected out of our evolutionary development

1955 child-development study

-- 698 children on Kauai island of Hawaii, studied their development for 40 years -- lead by Emmy Werner -- nurses and social workers observed the families and interviewed the children's mothers when the children were 1 year old and again when they were 10 years old -- researchers interviewed teachers about the children's academic performance and classroom behavior during elementary school years -- examined police, family court, and social service records involving the children as victims or perpetrators -- administered standardized intelligence and personality tests to the children when they were 10 and 18 years old and interviewed them at ages 18, 32, and 40 -- results: -- children who experienced prenatal or birth complications were more likely than others to develop physical handicaps, mental illness, and learning difficulties, but whether they developed such problems (and if so, to what degree) depended on their home environment -- parents' income, education, and mental health, together with the quality of the relationship between the parents influenced child development -- by age 2, toddlers who had experienced severe prenatal or birth problems but who lived in harmonious middle-income families were nearly as advanced in language and motor skills as were children who had not experienced early problems -- by age 10, prenatal and birth problems were consistently related to psychological difficulties only if the children also grew up in poor rearing conditions -- by age 10, most of the children who faced both biological and environmental challenges (prenatal or birth complications and adverse family circumstances) developed serious learning or behavior problems, and by age 18, most had a police record, experienced mental health problems, or became an unmarried parent. however, 1/3 of these at-risk children showed resilience and grew into young adults who, according to Werner, "loved well, worked well, and played well."

the newborn infant: negative outcomes at birth

-- Apgar score: method for evaluating the health of the newborn immediately following birth based on the skin tone, pulse rate, facial response, arm and leg activity, and breathing. perfect scores are rare (even a normal birth has a traumatic effect on the newborn), but consistently low scores are concerning -- common negative outcome: low birth weight -- infant mortality: death during the first year after birth (relatively rare in the industrialized world). in 2016 in the US, the infant mortality rate was 5.87 deaths per 1000 live births (far higher than that of other industrialized nations due to poverty with low-income mothers lacking health insurance and access to medical and prenatal care). in Afghanistan and Somalia, 1 of every 10 infants dies before age 1 -- low birth weight: average US newborn weighs 7.5 pounds (most between 5.5 and 10 pounds). infants who weigh less than 5.5 pounds at birth are considered to be of low birth weight, many of whom are premature or preterm (born at 35 weeks or earlier after conception). 1 out of 10 babies born in the US in 2017 was premature. other low birth weight infants are called small for gestational age (they may be either preterm or full term but they weigh substantially less than is normal for their gestational age). in 2017, 8.3% of US newborns were low birth weight. low birth weight newborns have a heightened level of medical complications, higher rates or neurosensory deficits, more frequent illness, lower IQ scores, and lower educational achievement. very low birth weight babies (weighing less than 3.3 pounds) account for 1.4% of live births in the US in 2017. causes are smoking, alcohol, and environmental pollutants like lead and mercury (eg. in China, high levels of air pollution have been linked to both low birth weight and preterm birth, likely due to impaired oxygen transport across the placenta). another cause is the skyrocketing rate of twin, triplet, and other multiple births (in 1980, 1 in every 53 infants born in the US was a twin. in 2017, 1 in every 30 infants was a twin). 55% of twins are low birth weight and higher than 95% of triplets and above are low birth weight. 8-year-old Australian children born low birth weight showed a greater incidence of sensory impairments, poorer academic achievement, and more behavior problems than term-birth peers. sample of term-birth families had higher educational attainment and employment status than preterm sample. German study showed that the strongest predictor of outcomes for very low birth weight infants is maternal education. other study showed link between very low birth weight and childhood psychiatric issues especially those involving inattention, anxiety, and social difficulties like ADHD and autism. causes could be white-matter reduction, ventricular enlargement, and other abnormal brain development outcomes. for the majority of low birth weight children, the negative effects of their birth status gradually diminish, generally ending up within the normal range on most developmental measures. Rumaisa (world's smallest surviving infant) and Hiba Rahman were born 15 weeks premature but reached appropriate developmental milestones in motor and language abilities. in a study of extremely low birth weight infants, by 18 to 22 months of age, 16% were unimpaired and 22% were only mildly impaired. parents are encouraged to have as much physical contact and social interaction with their hospitalized low birth weight infant as the baby's condition allows (kangaroo care) to decrease mortality and increase growth, breast-feeding, and attachment. breast milk promotes healthy brain development in preterm infants. being touched (cuddled, caressed, and carried) is a vital part of a newborn's life. one study showed that babies who experienced more gentle touching by caregivers in the NICU later showed stronger neural responses to touch than did babies who had less experience with gentle touching, and babies who had more painful experiences in the NICU later showed decreased brain responses to touch than did babies who experienced less pain. delaying of developmental milestones occurs (smiling does not happen around 6 weeks of age). premature babies are more likely to be victims of parental child abuse (recent study of infant hospitalizations due to child abuse found that the two strongest preceptors were preterm birth and extended stay in the NICU so interventions with parental training in child development, support sessions in the hospital and at home are developed.

Darwin's theory of evolution inspired the proposal of an intensive study of children's development to get insights into human nature

-- Darwin published an article, "a biographical sketch of an infant," in 1877, which presented his observations of the growth of his infant son, William (baby biography of William's day-to-day development) -- Darwin's theory of evolution influences developmentalists on infants' attachment to their mothers, innate fear of natural dangers like spiders and snakes, sex differences, aggression and altruism, and learning mechanisms

adaptive value of looking and acting young

-- Konrad Lorenz 1943: adults' feelings of nurturance and protection may be provoked by certain universal infantile characteristics. adults rate pictures of infant-like head-shapes as cuter than adult-like ones. adults may find young children's immature psychological characteristics endearing - aids survival of offspring and extended juvenile period -- three studies (one with American college students, one with American college student and parents of young children, one with Spanish college students): adults evaluated vignettes containing hypothetical children expressing immature (agentive with intention or nonagentive with just poor information processing) or mature cognition. adults selected the child that reflected each adjective or statement in a series following the vignettes. adjectives were grouped into positive affect, negative affect, and intelligence. results were that intelligence was picked for mature cognition, positive affect was chosen for agentive cognition, and negative affect was chosen for nonagentive cognition

the newborn infant: multiple-risk models

-- Michael Rutter 1979 reported a heightened incidence of psychiatric problems among English children growing up in families with four or more risk factors (marital distress, low SES, paternal criminality, and maternal psychiatric disorder) -- risk factors for fetal development are more likely experienced by women living below the poverty line (eg. in Japan) -- African American infants born in communities with higher levels of structural racism are more likely to be small for gestational age than African American infants born in communities with lower levels of structural racism -- pregnant women in minority communities who report higher levels of concern about racial discrimination are more likely to have preterm infants -- developmental resilience caused by certain personal characteristics (intelligence, responsiveness to others, a sense of being capable of achieving their goals) and responsive care from someone

protection from over stimulation

-- Turkewitz and Kenny (1982): infancy limitations allow one sensory system to develop without having to compete for neural resources (neurons) with another, usually later-developing system -- sensory systems develop in an invariant order (eg. audition before vision) -- when the tops of eggshells of bobwhite quails were removed, they showed enhanced visual discrimination abilities but impaired auditory attachment behavior -- premature human infants are exposed to a host of tactile, auditory, and visual stimuli months before the brain expects them to experience some similar impairments and exceptionalities

how much trust should social policy put into preschoolers' courtroom testimony?

-- about 100,000 children testify in legal cases each year. many of these children are very young (more than 40% of children testifying in sexual-abuse trials are younger than 5 years old according to Bruck, Ceci, & Principe 2006) -- one experiment: researchers tested whether biased questioning affects the accuracy of young children's memory for events involving touching one's own and other people's bodies. the researchers began by having 3- to 6-year-olds play a game like Simon Says in which they were told to touch various parts of their body and those of each other. a month later, a social worker was sent to interview the children about their experiences during the game (Ceci & Bruck 1998). before the interviews, the social worker was given a description of each child's experiences, but unknown to her, the description she heard included inaccuracies. the social worker was given instructions much like those in a court case ("find out what the child remembers"). the version of events the social worker had heard often influenced her questions (eg. if children's accounts contradicted what the social worker believed to be true, she tended to question the children repeatedly, which lead to the children often changing their responses with 34% of 3- and 4-year-olds eventually corroborating at least one of the social workers' incorrect beliefs. children were led to "remember" not only plausible events that never happened but also implausible ones like their knee being licked and a marble being inserted in their ear. -- when 3- to 5-year-olds are not asked leading questions, their testimony is usually accurate as far as it goes even though they leave out a great deal of information -- when prompted by leading questions, young children's testimony is often inaccurate especially when the questions are asked repeatedly -- the younger the children are, the more their recall tends to reflect the interviewer's biased questions -- realistic props (like anatomically correct dolls and drawings) do not improve recall of events that occurred but actually increase the number of inaccurate claims -- this research has resulted in many judicial and police agencies revising their procedures for interviewing child witnesses to incorporate the lessons of this research

in what ways is development continuous, and in what ways is it discontinuous?

-- are there distinct discontinuous changes that fundamentally reorganize into an entirely different thing (eg. phases of water)? -- early experience is absolutely fundamental if development is continuous and adds onto the early experiences continuous development: the idea that changes with age occur gradually, in small increments; relatively steady rate over time; cumulative process of adding more of the same type of skill (example from lecture: you can increase the size of the muscles you already have with continuity (gradual cumulative change)) discontinuous development: the idea that changes with age include occasional large shifts; in stages; common observation that children of different ages seem qualitatively different; new ways of understanding and interacting with the world (Piaget's conservation-of-liquid-quantity problem is often used to exemplify the idea that development is discontinuous and is a classical technique designed to test children's level of thinking; younger children think taller glass has more liquid while older children know the amounts of liquid in the glasses are equal) -- example from lecture: first steps are not better or more crawling; first steps are their own thing; you go distinctly from being unable to walk unsupported to being able to walk unsupported (discontinuity); however, esther thelen looked at infants' stepping reflex (when you hold an infant up, they show a reflex to stepping on the surface below them even though they can't support themselves; the reflex goes away; and then the ability comes back with first steps (U-shaped function); thelen put infants without the reflex into water (there's buoyancy) and when they touch the bottom, they have the stepping reflex again; the stepping reflex only goes away because their thighs have enough body fat that they are too difficult to lift in that way -- the problem with saying the development of a pine tree is always continuous: it starts as a seed that then goes through fundamental reorganization to sprout a plant -- butterfly development is discontinuous -- continuity vs. discontinuity depends on timespan (things look more discontinuous over longer periods of time and more continuous over shorter periods of time) -- exanoke: Tanner 1961 study in which the question was whether children's height increases continuously or discontinuously. when one looks at the boy's height at each age, development seems smooth and continuous with growth occurring rapidly early in life and then slowing down. when one looks at the amount of change in the same child's height from one year to the next over the same period, development seems like there is rapid growth during the first 2.5 years, then slower growth, then a growth spurt in adolescence (13 to 15), and then a rapid decrease in growth -- differences between how an uncle sees his niece when he only sees her every 2 to 3 years and how parents see her when they see her every day -- stages in stage theories: distinct and separate period of development (fundamental reorganizations/discontinuous; characterized by qualitative changes, discontinuities, clear-cut boundaries with clear beginning and end points, uniform "nature" within a stage or clear characteristics at that period, universal across children and cultures) -- examples: piaget's theories of cognitive development, Lawrence kohlberg's theory of moral development, freud (theory of psychosexual development), Erickson (theory of psychosocial development) -- jean Piaget's theory: between birth and adolescence, children go through four stages of cognitive growth, each characterized by distinct intellectual abilities and ways of understanding the world. 2- to 5-year-olds can focus on only one aspect of an event or one type of information at a time. by age 7, children can simultaneously focus on and coordinate two or more aspects of an event and can do so on many different tasks. for the conservation-of-liquid-quantity problem, most 4- and 5-year-olds focus only on height. most 7- and 8-year-olds consider both relevant dimensions simultaneously -- most common stage marker: chronological age (correct for prematurity with young infants) -- periods of development: prenatal (conception through birth; inside vs. outside is a big discontinuous change; things reorganize on a very predictable schedule; that's why they can date the birth of an infant within a few days; we go from not having hands to having hands); infant and toddler (birth to age 2; infant means without language; toddlers acquire language); early childhood (ages 2 to 6); middle childhood (ages 6-11); adolescence (ages 11 to 20); adulthood (there are theories that differentiate stages of adulthood like middle age and old age) -- more recent theories (within the past 20 years) take a more continuous approach. development occurs skill by skill (evidence: a child often will behave in accordance with one proposed stage on some tasks but in accordance with a different proposed stage on other tasks; variable level of reasoning)

romanian adoption study

-- children whose early life was spent in horribly inadequate orphanages in Romania in the late 1980s and early 1990s. children in these orphanages had almost no contact with any caregiver. the dictatorship demanded that staff workers not interact with the children even when giving them their bottles. staff members provided the infants with so little physical contact that the crown of many infants' heads became flattened from the babies' lying on their backs for 18 to 20 hrs per day -- some of these children were adopted by loving families in Great Britain, arriving severely malnourished with more than half being in the lowest 3% of children their age in terms of height, weight, and head circumference. most also showed varying degrees of intellectual disability and were socially immature -- 150 of the Romanian-born children were studied at age 6 in comparison to a group of British-born children who had been adopted into loving British families before 6 months of age -- while the physical development of the Romanian-born children had improved considerably, their early experience of deprivation continued to influence their physical development -- if adopted before 6 months of age, they weighed about the same as British-born children when both were 6-year-olds -- if adopted between 6 months and 24 months of age, they weighed less -- if adopted between 24 months and 42 months of age, they weighed even less -- same pattern for intellectual development, and the intellectual deficits of the Romanian children adopted after 6 months of age were just as great when the children were retested at age 11 but by the time the children had become young adults (22- to 25-year-olds), their intellect was in the normal range -- social development was damaged for the longest (almost 20% of whom were adopted after 6 months of age showed extremely abnormal social behavior at 6 years like not looking at their parents in anxiety-provoking situations and willingly going off with strangers while 3% of the British-born children did so) -- even in early adulthood, many had difficulty controlling their emotions and forming friendships. they had far greater rates (43%) of using mental health services than those in the control group (10%). the differences in mental health problems increased between ages 15 and 23 years -- abnormal brain activity: brain scans at 8 years old showed that children who lived in the orphanage the longest had unusually low levels of neural activity in the amygdala. similar brain abnormalities as children who spent their early lives in poor-quality orphanages in Russia and east Asia

nature and nurture (genes)

-- constant interaction between nature and nurture (example: prenatal stress, which is stress that the mother is experiencing, and developmental risk study in 2018 said having prenatal stress increases plasticity, looked at how low prenatal stress in voles, a type of rodent because humans and rodents are similar, means having less contact care does not matter but having high prenatal stress and high contact care have better stress resilience and having high stress and low contact care had negative effects so being a responsive parent is a good thing) -- our modern understanding of how characteristics are transmitted from parent to offspring originated with Gregor Mendel. in the 1950s, James Watson, Francis Crick, and Rosalind Franklin identified the structure of DNA -- human gene synthesis: first genome-edited newborns in November 2018 (one twin's genes were edited to resist HIV) -- on chromosomes: 20-21,000 protein-coding genes (affected by epigenetics, usually prenatally. Turned on or off to determine gene expression) -- The 23rd chromosome pair determines your biological sex (females have XX and males have XY. The Y chromosome is physically smaller than the X chromosome and has fewer genes. There are genes on the X chromosome that aren't on the Y (X-linked). Males are more likely to be red-green colorblind or express other X-linked genes because they only need the gene to be on their one X chromosome while females need the X-linked gene on both of their X chromosomes to express the gene. Hemophilia is X-linked. Adaptive advantage for red-green colorblindness to identify camouflage better. Females tend to be carriers for X-linked traits) -- PKU, phenylketonuria, is a genetic disorder related to a defective recessive gene on chromosome 12 that causes an inability to metabolize an amino acid, phenylalanine, that is in red meat and in aspartame, an artificial sweetener (all US children tested for this at birth because if their diet involves these amino acids, they will experience impaired brain development and intellectual disabilities); 5-HTTP serotonin transporter gene relates to functioning in the serotonin system and involves interaction with childhood adverse events (long allele makes people less susceptible to anxiety and depression unless they have much higher childhood adverse events; short allele makes people more susceptible to anxiety and depression) -- gene-environment correlations: genes and environment tend to co-occur (passive: parent with musical genes is more likely to have music around the house; or active: genetic makeup for higher physical activity level makes you more likely to seek out physical activities) -- transmissions of genes from parents to child through their genotypes -- endophenotypes: unobservable, intermediate phenotypes, most notably the brain and nervous system, that do not involve overt behavior -- in embryological development, the genes that are turned on in certain cells lead them to specialize for arm, hand, and fingerprint formation. the turning on and off of genes is conducted by regulator genes as a part of a chain of genetic events. thalidomide interferes with the functioning of genes underpinning normal growth factors. early visual experience is necessary for the normal development of the visual system because it causes the switching on of certain genes, which switch on other genes in the visual cortex. ramifications of decreased visual experience are observed with children with cataracts -- 1/3 of human genes have two or more different alleles -- variability in human intelligence is currently believed to be linked to more than 500 different genes (polygenic inheritance) -- carrier genetic testing is typically offered to people of Eastern European Jewish descent because of their increased likelihood of carrying the recessive gene for Tay Sachs, a severe birth defect that culminates in death by age 5. also typically offered to people of African descent because of their increased likelihood of carrying the recessive gene for sickle-cell disease in which red blood cells have an atypical sickle shape causing chronic anemia and pain. some prospective parents opt for in vitro fertilization with preimplantation genetic diagnosis -- prenatal testing assesses risk for a range of genetic disorders. prenatal screening tests analyze maternal blood for information about degree of risk. non-invasive prenatal testing uses fragments of fetal DNA that enter the mother's bloodstream; can be used as early as the 9th week of a pregnancy to test for aneuploidy (missing or extra chromosomes), which is associated with Patau syndrome, Edwards syndrome, and Down syndrome depending on the location of the aneuploidy. prenatal diagnostic tests (more invasive) detect genetic anomalies using fetal cells from the placenta (chorionic villus sampling, usually done between 10 and 13 weeks of pregnancy) or from amniotic fluid (amniocentesis, usually done between 15 and 20 weeks of pregnancy -- newborn screening is the largest genetic testing program in the US. newborns receive a tiny pinprick to their heel to get a blood sample, which is then tested for 30 to 50 different genetic and non-genetic disease biomarkers including PKU. recent study suggests that genomic sequencing of newborns illuminates a range of potential health issues not detected by current newborn screening protocols -- study focused on the MAOA gene, an X-linked gene that inhibits brain chemicals associated with aggression. young men who had a relatively inactive version of that gene and who had experienced severe maltreatment grew up to be more antisocial than other men who had also experienced severe maltreatment but who possessed a more active version of that gene. 85% of the maltreated group with the relatively inactive gene developed some form of antisocial behavior and were almost 10 times more likely to be convicted of a violent crime -- parents' behavior toward their children is genetically influenced as are the kinds of preferences, activities, and resources to which they expose their children (dyslexic parents are less likely to provide a reading-oriented environment for their children). a study characterized the genotypes of a child and their two biological parents and found that the child's educational outcomes were predicted in part by parental alleles that the child did not inherit because of the role they played in the creation of the child's environment (genetic nurture) -- epigenetic mechanism: methylation silences gene expression as a function of maternal behavior. methyl molecules block transcription in the promotor region of the gene, turning off gene activity. provide evidence of longterm epigenetic effects of early adverse experiences on gene expression, impacting later health and wellbeing. children who experienced severe early-life stress in the form of child maltreatment show patterns of methylation in the glucocorticoid receptor gene. recent study where researchers used a whole-genome screen to examine both methylation and gene expression in a group of 9- to 12-year-old girls who had experienced levels of childhood adversity ranging from mild to severe. more than 100 genes had methylation levels that varied according to the amount of stress the girls had experienced. another study revealed epigenetic changes related to childhood abuse in the sperm cells of adult males (plausible epigenetic route for the cross-generational transmission of stress)

cross-sectional research design

-- cross-sectional: groups of different ages studied at the same time -- more common than longitudinal -- example: Evans, Xu, and Lee 2011 had Chinese 3-, 4-, and 5-year-olds play a game in which winning a prize required guessing the type of object hidden under an upside-down paper cup. before the child could guess, the experimenter said she needed to leave the room and asked the child not to peek while she was gone, which spilled candies out. at all ages, many children peeked and then denied doing so. 5-year-olds lied more often (for example, explained the candies by saying they accidentally knocked over the cup or ate the candies to get rid of the evidence). 3-year-olds were the least-skilled liars, generating implausible excuses -- eliminates selective attrition, practice effects, and theory change -- advantages: great way to find age differences, good for examining normative (average) differences between children of different ages, economical (doesn't take a lot of time or money) -- you're not expecting people to come back time after time, participants won't get familiar with the test because they won't be taking it multiple times, identify average age differences (compare average 3-year-old to average 6-year-old to average 8-year-old) and normative development, doesn't require as many resources -- disadvantages: ignores the processes underlying differences (only looks at the person at that time and not how the person changed into that state), confounds age and cohort effects (cohort is generation; can't tell if results are due to maturational or generational differences), do not yield information about the stability of behavior over time or about the patterns of change shown by individual children -- example of cohort effect: researcher wanted to look at differences between gates (how they walk), women were walking in a toed-out manner (pointing them outwards a little bit), that particular group had been taught etiquette and comportment and that they had to walk toed-out to be "lady-like" as a child, you would think that was an age effect if you hadn't known that -- a hurricane or pandemic affecting only the cohort is another example of a cohort effect

three advantages of knowing theories of child development from the textbook

-- developmental theories provide a framework for understanding important phenomena -- they raise crucial questions about human nature -- they lead to a better understanding of children

effective alternatives to spanking (Denham 1998, 2006)

-- expressing sympathy (when parents respond to their children's anger with sympathy, the children are better able to cope with the situation causing the distress) -- helping angry children find positive alternatives to expressing their feelings (eg. encouraging them to do something they enjoy helps them cope with their hostility) -- time-outs -- demonstration of these strategies when used by day-care personnel and teachers (Denham 1996): -- special curriculum devised for helping preschoolers (3- and 4-year-olds) who were angry and out of control: encourages preschool teachers to help children recognize their own and other children's emotions as well as teach children techniques for controlling their anger and peaceably resolving conflicts with other children -- turtle technique: when children felt themselves becoming angry, they were to move away from other children and retreat into their turtle shell where they could think through the situation until they were ready to emerge from the shell -- curriculum was successful: children became more skillful in recognizing and regulating anger when they experienced it (eg. one boy who had regularly gotten into fights when angry told the teacher after a dispute with another child, 'see, I used my words, not my hands' (Denham 1998)) -- benefits can be long term (one test: positive effects were still evident as long as 4 or 5 years after children completed the curriculum (Jennings & Greenberg 2009))

adaptations of infancy and childhood

-- extended immaturity has a high degree of plasticity and allows children the time and flexibility necessary to master complex skills -- opportunity for play, adaptive value of neural inefficiency, the benefits of thinking you're better than you are, and the adaptive value of looking and acting young -- however, maturity is still the goal of development

behavior genetics: quantitative genetics research designs

-- family study design: whether phenotypic traits are correlated with the degree to which people are genetically related. resulting correlations are compared to see if they are higher for more closely related individuals than for less closely related people and higher for individuals who share the same environment than for individuals who do not -- twin study design: involves equal environments assumption for identical and fraternal twins (questioned because parental treatment of identical twins may be more similar than that of fraternal; notable differences in the degree of placental sharing among identical twins because many fully share it and others don't) -- adoption study design: adopted children's scores on a measure are correlated more highly with those of their biological parents and siblings or with those of their adoptive parents and siblings -- adoption twin study design (ideal): identical twins who grew up together are compared to identical twins separated at birth and raised apart (however, children's phenotypes shape their environments and adoption agencies typically place separated twins with families of backgrounds similar to one another)

longitudinal sequential or accelerated longitudinal research design

-- follows groups for a period of time -- helps examine cohort effects -- can make longitudinal and cross-sectional comparisons -- more efficient -- advantages: can differentiate age, time, and cohort effects and can look at a wider age range of subjects over a shorter time interval -- disadvantages: costly in time, effort, and money and it requires more sophisticated and advanced statistical training for data analysis -- marrying longitudinal studies and cross-sectional (longitudinal sequential/accelerated longitudinal); easier to get people to commit to the study; costly in terms of effort -- start with groups at different ages and follow them over a shorter period of time -- example: collect data for a group of 5-year-olds through them becoming at least 8-year-olds, start with a group of 8-year-olds and follow them through them becoming at least 11-year-olds, start with a new group of 11-year-olds, etc.

effects of educating babies

-- formal learning experiences early in life can have negative effects -- Harlow (1959): rhesus monkeys were given a discrimination-learning task (teaching monkeys to choose among varied stimuli. after 120 days, the task given was more complicated) beginning at different ages ranging from 60 to 366 days. the younger the monkey was when training began, the worse the monkey performed on later learning tasks -- Papousek (1977): conditioned infants to turn their heads to the sound of a bell. infants began training at birth, 31, or 41 days of age. infants who learned from birth needed more days to learn the task than infants who began training at an older age -- Zimmerman, Christakis, and Meltzoff (2007): every hour of baby DVD/video that infants watched correspond to about 6 to 8 fewer words in their receptive vocabularies -- the quality of children's play at 12, 24, or 36 months and their focused attention was negatively affected by having the TV on in the background even if they paid little attention to it

developmental theories (general overview)

-- functions/tasks: describe change within one or several areas of behavior, describe changes in relations among areas of behavior, explain described/observed course of development

behavior genetics: environmental effects

-- growing up in the same family (positive emotion in infancy due to shared-environment because fraternal and identical twins were equally similar in measures of positive affect) -- birth order (different parental treatment due to different parental behavior and traits) -- idiosyncratic life events (getting bullied, having an inspiring teacher, serious accident)

why study child development?

-- improves child rearing/raising (parents, teachers) -- promotes adoption of wiser social policies regarding children's welfare (future oriented/humanitarian, government funding for research and initiatives like headstart programs, mandatory preschool, school-lunch programs, after school programs, practical issues like age a person should be before being tried for murder as an adult and child witnesses (four-year-olds can be relatively good witnesses but their memories are malleable) -- answers basic questions about human nature

protection from effects of deleterious early environments

-- increased neural plasticity lets children recover from severe early deprivation -- Harlow, Dodsworth, and Harlow 1965: monkeys isolated early in life grew up to be socially and behaviorally abhorrent -- Suomi and Harlow (1972): if isolated monkeys were given daily social contact with a younger, socially inexperienced peer, the effects of early social isolation could be reversed -- early studies of childhood deprivation in orphanages indicated that effects were permanent, but Romanian adoption study showed otherwise

microgenetic research design

-- large number of observations/measurements over a very short time interval (around a transition period) -- are typically used when the basic pattern of age-related change has already been established and the goal becomes to understand how the changes occur -- try to target an important transition period (onset of walking, beginning understand of addition) and provide an in-depth depiction of the processes that produce change -- recruits children thought to be on the verge of an important developmental change, heightens their exposure to the type of experience that is believed to produce the change, and then intensively study the change as it is occurring -- example: Siegler and Jenkins 1989 studied how young children discover the counting-on strategy for adding two small numbers after spending the previous time counting from 1. researchers selected 4- and 5-year-old children who added by counting from 1 and studied them over an 11-week period, giving them many addition problems several times per week and video recording their behavior on every problem. children often discovered the counting-on strategy while solving easy problems that they previously solved correctly by counting from 1. their first use of the counting-on strategy was often accompanied by insight and excitement, but they only gradually increased their use of the new strategy on subsequent problems, though they eventually used it quite often -- relatively small number of participants in the study (average smaller sample size) -- practice effects: extra practice may be driving the change instead of natural development -- need an accurate sense of when the change will occur and whether the participant will undergo the transition period during the study's time window -- hard to analyze and interpret the data -- more likely to draw continuity and gradual change from microgenetic designs -- advantages: great for understanding what causes a transition (can really help us understand developmental change) and not as costly as longitudinal designs in money or time -- disadvantages: hard to determine transition points (how long will change take?), practice effects, can be expensive (need to have lots of time in a short period), can only use this approach for a few subjects (can't use some statistical techniques to analyze the data)

developmentally appropriate programs vs. direct-instructional programs in preschool

-- little consistent differences following one year of education -- after greater than one year, academic attainment was greater for children in the developmentally appropriate programs than in the direct-instructional programs -- children attending developmentally appropriate programs experience less stress, like school better, are more creative, and have less test anxiety -- any academic benefits gained from a teacher-directed program had its costs in terms of motivation

research designs specific to studying development

-- longitudinal -- cross-sectional -- longitudinal sequential (accelerated longitudinal) -- microgenetic

longitudinal research design

-- longitudinal: -- study same set of people over time at regular intervals, can be of any time length (often a few weeks or months, which is short-term, but can go on for years or decades; according to the textbook, usually at least a year) -- example: Brendgen and colleagues' 2001 study where each child's popularity was examined each year from age 7 to age 12. popularity seemed stable. some individuals showed idiosyncratic patterns of change -- example: development of children in Kauai from before birth to age 40 -- used primarily when the main issues are stability and change in individual children over time -- advantages: -- identify common patterns and individual differences -- learn a lot about process of change -- study relationship between early events and later behavior -- example: emmy warner's children of the garden island study; many nordic studies -- problems -- difficult task of locating the children for each re-examination -- biased sampling (need people to agree to join the study; not everyone asked will say yes; important differences between people who agree and those who don't -- selective attrition (people drop out; they change their mind; they move away; important differences between people who dropped out and those who stayed) -- practice effects (eg. every time you take an IQ test, you do better on it because the test is familiar) -- cohort effects (common shared experience with the group you're studying that isn't common among all people) -- science is constantly evolving so over time so the theory your questions are based on could change and become outdated -- new york longitudinal temperament study (manhattan), involved decades, kept the same research assistants to motivate participants to come back, which required more resources

perspective of evolutionary developmental psychology

-- natural selection operates at all stages of development, not just adulthood -- selection has its greatest effects on the early stages of ontogeny -- Geary 1998: testosterone provides early benefits for male humans associated with social status and dominance but may suppress the immune system and increases risks of cancer and heart disease later in life -- organisms are at greater risk of death early in life, especially Homo sapiens with their extended developmental periods

brain development: developmental processes

-- neurogenesis begins 42 days after conception and is virtually complete by the midway point of gestation. most of the roughly 100 billion neurons you currently posses have been with you since before you were born. however, humans do continue to generate new neurons throughout life, particularly in the hippocampus (a brain area that is heavily involved in memory processes). adult neurogenesis is affected by environmental factors: it increases under rewarding conditions and decreases in threatening environments -- after their birth, neurons migrate to their ultimate destinations, which is typically outwards from the center of the brain toward the developing neocortex. early in gestation, the brain is very small so the distances traveled are quite short but as the brain grows, neurons require guides (glial cells). once they reach their destinations, they first grow an axon and then a bush of dendrites. then, they take on the specific structural and functional characteristics of the different structures of the brain. axons elongate as they grow toward their targets. dendrites experience arborization, an enormous increase in the size and complexity of the dendrite "tree" that results from growth, branching, and the formation of spines on the branches. arborization increases the dendrites' capacity to form connections with other neurons. as arborization allows neurons to grow in complexity over the first several years of postnatal life, the cortex grows in surface area and the layers of the cortex become thicker -- myelination begins prenatally and continues into early adulthood (are white; white matter); begins deep in the brain and moves upward and outward into the cortex. occurs rapidly in the first few months after birth, slows somewhat during toddlerhood, and continues slowly into young adulthood. sensory areas of the brain mature sooner than the executive function areas -- synaptogenesis: neurons forming synapses with each other. begins prenatally and proceeds very rapidly before birth and for some time afterward. synapse generation is complete much earlier in the sensorimotor cortex than in the frontal area -- for myelination and synaptogenesis, the differential timing likely contributes to the developmental timing of the onset of various abilities and behaviors -- synapse elimination: 40% (the excess) is eliminated through synaptic pruning. brain undergoes waves of synaptogenesis and synaptic pruning in the first months and years of life but the brain also undergoes substantial changes during adolescence. outer layers of the cortex shrink at a faster rate during adolescence than during either childhood or early adulthood. last area of the cortex to mature is the dorsolateral prefrontal cortex, which does not reach adult dimensions until after age 20. synaptic pruning continues until individuals are in their 30s. young children with autism have larger brains and studies suggest they have greater synaptic densities in some areas and increased cortical thickness (possible reduced or delayed rates of synaptic pruning). possible excessive pruning in adolescence for schizophrenia

adaptive value of neural inefficiency

-- newborns are neurologically immature and remain that way for months, necessary result of being born too early (skull would be too big to fit through birth canal) -- much of brain development occurs postnatally, making the infant's nervous system immature

behavior genetics: heritability

-- one meta-analysis of more than 17,000 traits (more than 14 million twin pairs) found that heritability was greater than zero for every trait (psychological traits like temperament, personality, cognition, psychopathology) investigated in the analysis -- identical twins resemble each other in IQ more than do same-sex fraternal twins. however, identical twins are not identical in terms of IQ -- applies only to a particular population living in a particular environment. in North America and Europe, heritability of height is at around 90% but if some segment of the population experienced a severe famine during childhood and the rest had remained well-fed, the variability due to environmental factors would increase dramatically -- heritability estimates may appear larger within populations with more homogenous environments -- as twins get older, the degree of variance in intelligence accounted for by their genetic similarity increases. older people have more choices with regard to their educational experiences and thus more opportunities to follow their one genetically mediated preferences for academic pursuits

one problem that confronts all parents: how to help their children control their anger

-- one reaction is to spank children who express anger in inappropriate ways (fighting, name calling, talking back) -- study with representative US sample: 80% of parents of kindergarten children reported having spanked their child on occasion and 27% reported having spanked their child the previous week (2012). spanking made the problem worse. the more often parents spanked their kindergartners, the more often the same children argued, fought, and acted inappropriately at school when they were third graders. this relation held true for black, white, hispanic, and asian people alike, and it held true above and beyond the effects of other relevant factors such as parents' income and education

benefits of play

-- play accounts for 10-40% of children's time and energy expenditure -- juvenile apes, wild dogs (canids), dolphins, and elephants spend large proportions of their time and energy playing -- spontaneous, voluntary, engaging, effortful -- most common type of play in early life: locomotor play, which includes vigorous movements (chase games) and rough-and-tumble play (play fighting), is often social -- object play: manipulation of objects in the environment, may foster tool use and construction (eg. children who play with objects are later more likely to successfully use those objects as tools in a toy-retrieval task and are more successful on a simple tool-use task -- play involves engaging in novel behaviors, and if those behaviors are beneficial, they may spread throughout the group -- symbolic/fantasy play involves pretending and is likely unique to humans, is first seen at 18 months of age, becomes more complex with age, is usually social, involves other types of play, helps children understand adult roles, increases over preschool and early school years and decreases as games (play with rules) increases -- only humans play throughout life (into adulthood)

the adaptive value of thinking you're better than you are

-- preschool children overestimate their abilities (accuracy in predicting and evaluating their own performance increases with age) -- younger children think they have better memories, greater physical abilities, are more skilled at imitating models, know more about how things work, are smarter, and rate themselves as stronger, tougher, and of higher social standing than older children think of themselves -- Bandura (1997): it's important to develop a positive sense of self-efficacy, or a perspective of seeing oneself as being a person in control of one's life -- over-optimism serves as a motivating factor for trying new things they wouldn't otherwise try and persist at tasks older children may quit -- Bjorklund 1993: 3, 4, and 5 year old children watched a model perform two tasks with different levels of difficulty: juggling 1, 2, or 3 balls and throwing balls in a basket from three different distances. they were asked to predict how well they would do on these tasks and how well they did afterward. children overestimated (more when they were younger). 3 and 4 year old children overestimated more when they had higher IQ scores. 5 year olds overestimated more when they had lower IQ scores -- kindergarten first and third grade children were given five sort-recall memory trials using different sets of categorically related words and asked to predict how many items they would remember beforehand. strategies were assessed during study of the words and recall. they were classified into high and low accuracy groups. children in low accuracy showed greater gains in recall over the 5 trials

theme #7: research and children's welfare

-- program for helping children deal with their anger and the recommendations for fostering valid eyewitness testimony from young children -- educational innovations: children's reasoning, remembering, conceptualizing, and problem solving are inherently related to education -- Carol Dweck and colleagues 2012 have found that that some believe intelligence is fixed while others see it as changeable with time and effort put into learning as the key determinant (the latter react to failure with persistence and more effort while the former tend to give up when they fail) -- Blackwell, Trzesniewski, and Dweck 2007 devised an effective educational program for middle school students from low-income backgrounds. they presented one group with research findings about how learning alters the brain in ways that improve subsequent learning and thus makes you smarter. the other group was presented with research findings about how memory works. former group improved their math grades and children going from seeing intelligence as fixed to changeable showed especially large improvements. teachers cited more than three times as many students from the former group as showing unusual improvement in motivation or performance -- presentation of struggle stories (famous people had to overcome failures) improves children's science learning. how might what we have learned be used in education/healthcare? how can the science of child development improve the lives of children?

importance of science and research methods

-- science vs. advice (even though john watson claimed to only care about science, he gave bad parenting advice that was not based in advice -- instead, being emotionally responsive is good parenting) -- knowing why we believe that something is true is fundamentally important -- scientific method: an approach to testing beliefs that involves choosing a question to be answered, formulating a hypothesis regarding the question, developing a method for testing the hypothesis (what distinguishes scientific research from non-scientific approaches), and using the resulting data to draw a conclusion regarding the hypothesis -- basic assumption: all beliefs may be wrong and must be viewed as hypotheses (testable predictions of the presence of absence of phenomena or relations rather than as truth) -- research has shown: kindergartners who are aware of the component sounds within words later tend to read more skillfully than their peers who lacked this ability as kindergartners. this pattern exists in the US, Australia, Norway, and Sweden -- weight gain is an inadequate measure of nutrition (many people who consume large amounts of junk food are obese yet malnourished) -- key criterion for measurement: -- the measure must be directly relevant to the hypothesis -- reliability (degree to which independent measurements of a behavior are consistent); interrupter reliability is how much agreement there is in the observations of different raters who witness the same behavior; test-retest reliability is when measures of a child's performance on the same test, administered under the same conditions, are similar on two or more occasions -- validity (degree to which the test measures what is intended to measure); internal validity is whether effects observed within experiments can be attributed with confidence to the factor that the researcher is testing; external validity is the ability to generalize research findings beyond the particulars of the research in question (findings of a single experiment are the first step; additional studies with participants from different backgrounds and with varying research methods are needed) (reliability is needed for internal validity, and both are needed for external validity)

hazards to prenatal development (teratogens)

-- teratogen: environmental agent that causes damage during prenatal phase -- thalidomide would suppress nausea; used most in the early 1960s; prescribed for morning sickness; it was a teratogen that interfered with formation of limbs; thalidomide babies born with major deformities in arms or legs (no arms; flipper like hands growing from their shoulders) when taken between the 4th and 6th week after conception; a women taking thalidomide during the fetal stage did not affect the fetus negatively -- high doses of radiation or high exposure of lead are never good -- more of the teratogen tends to lead to greater damage (dose-response relation); heredity (genetic predisposition) affects teratogens' effects as does gestational age (sensitive periods) -- sleeper effects: the impact of a given agent may not be apparent for many years (between the 1940s and 1960s, the hormone diethylstilbestrol (DES) was commonly used to prevent miscarriage and had no apparent ill effects on babies. however, in adolescence and adulthood, these offspring turned out to have elevated rates of cervical and testicular cancer) -- if the mother is malnourished, it is more likely that teratogens will cause more damage -- teratogens frequently occur in combination (eg. families living in poverty experience poor maternal nutrition, exposure to pollution, inadequate prenatal care, psychological stress) -- painkillers, tylenol, ibuprofen, acne medication isotretinoin (accutane), marijuana (legal drugs, prescription and non-prescription), cocaine/illegal drugs (cocaine babies in the late twentieth century had brain development and stress response problems), second hand smoke and tobacco, alcohol, X-ray exposure (Broaders' uncle is missing vertebrate in his back because his mom got an X-ray while pregnant), mercury (environmental pollution), maternal flu exposure (maternal disease), fifth disease (in children, it's benign - flushed cheeks and fever - but in the second trimester, it causes an increased risk of miscarriage), maternal diabetes can be teratogens -- in 2015, 4.7% of pregnant women in the US reported that they used illicit drugs during their pregnancy -- treatment for depression during pregnancy can help reduce the risk of postpartum depression, which affects 10-30% of new mothers and is especially likely for women with previous histories of depression. in the US, 7% of pregnant women take antidepressant medication. -- opioids: prescription (Vicodin, Percocet, oxycodone, fentanyl) and illicit (heroin). fetuses can become addicted to them prenatally. neonatal abstinence syndrome is a form of drug withdrawal seen when fetuses exposed to opioids in the womb are born. between 2004 and 2013, rural US saw a 700% increase in the prevalence of NAS. West Virginia reported an NAS incidence rate of over 5% of all live births in 2017. effects of NAS include low birth weight, problems with breathing and feeding, and seizures. treatment for these newborns often requires medications like methadone or morphine to manage withdrawal symptoms. co-presence of other maternal drug use like antidepressants or marijuana increases likelihood newborn will have NAS -- from 2002 to 2014, marijuana use among pregnant women nearly doubled with the highest rate (7.5%) among 18- to 25-year-olds. some studies suggest the combination of marijuana and tobacco is particularly problematic. prenatal exposure to marijuana is associated with a range of problems involving attention, impulsivity, learning, and memory in older children -- cigarettes (nicotine) and alcohol wreak the most widespread havoc on fetal development. when a pregnant woman smokes a cigarette, both she and her fetus get less oxygen. the fetus makes fewer breathing movements while its mother is smoking and metabolize some of the cancer-causing agents contained in tobacco. secondhand smoke has an indirect effect on fetal oxygen too. main developmental consequences of maternal smoking are slowed fetal growth and low birth weight. smoking is linked to increased risk of sudden infant death syndrome, lower IQ, hearing deficits, ADHD, cancer, and stillbirths (there is a dose-response relationship). 7.2% of pregnant women in the US smoked in 2016. nicotine in any form (eg. e-cigs) can affect fetal cardiac, respiratory, and nervous systems -- sudden infant death syndrome: sudden, unexpected, and unexplained death of an infant younger than 1 year. an apparently healthy baby, usually between 2 and 5 months of age, is put to bed for the night and found dead in the morning as the most common SIDS scenario. in 2016, 1,500 US infants died of SIDS, making it the leading cause of infant mortality unrelated to congenital issues or prematurity. causes likely involve an interaction between an underlying biological issue that places the infant at risk and an environmental stressor (eg. limited access to oxygen due to an obstruction of the nose and mouth). recent research suggests at least some who died from SIDS had less serotonin, which may make it more difficult for young infants to detect and respond to a lack of oxygen by turning their head away from bedding or other soft materials especially during sleep. a subset of cases result from a rare genetic mutation in the breathing muscles that puts infants at greater risk of respiratory challenge in situations that impair breathing. parents should remove any barriers to their baby's breathing. infants sleeping on their backs reduces the possibility of breathing obstructions. sleeping on their stomachs increases the risk of SIDS more than any other single factor. parents should not smoke around the baby. bedding should be firm (soft bedding can trap air around the infant's face). North American infants are now beginning to crawl slightly later than those in previous generations because of the back to sleep movement -- maternal alcohol use is the leading and most preventable cause of fetal brain injury (between 2011 and 2013, 1 in 10 pregnant women in the US reported consuming alcohol in the prior month. rates are highest in European countries (25% overall, 60% in Ireland) and lowest in countries in the Middle East where Saudi Arabia, Qatar, and Oman report rates of 0%. alcohol in pregnant person's blood crosses the placenta into both the fetus's bloodstream and the amniotic fluid. the fetus gets alcohol directly in its bloodstream and indirectly by drinking the alcohol in the amniotic fluid. fetus has less ability to metabolize and remove alcohol from its blood so it remains in the fetus's system longer -- fetal alcohol spectrum disorder (continuum of birth defects) -- fetal alcohol syndrome: characteristic facial structures (small eyes, absence or flattening of the vertical groove between the nose and upper lip, and a thin upper lip), varying degrees of intellectual disability, attention problems, and hyperactivity. between 1.1% and 5% of schoolchildren met diagnostic criteria for the disorder. even less than one drink per day or occasional binge drinking (four or more drinks on a single occasion) can have negative effects like low birth weight, increased risk for ADHD, and delays in cognitive development and school achievement -- environmental pollutants like a noxious mix of toxic metals, synthetic hormones, and various ingredients of plastics, pesticides, and herbicides in bodies and bloodstreams of Americans (eg. mothers whose diet was high in Lake Michigan fish with high levels of PCBs had newborns with smaller heads). air pollution from fossil-fuel-burning is associated with low birth weight and neurotoxicity and disproportionately affects low-income populations. different forms of pollution act in combination (eg. china's dramatic increase in pollution-related birth defects due to the unregulated burning of coal, water pollution, and pesticide use). 2014 water crisis in Flint, Michigan had high levels of lead in the local water supplies, which negatively affected intelligence and academic achievement as well as lead to the development of ADHD symptoms. dose-response relationship in terms of pregnancy risk with lead exposure: higher lead levels in the mother increase the risk of miscarriage, preterm birth, and low birth rate

twin studies

-- the Minnesota study of twins reared apart: -- more than 100 pairs of twins reared apart were brought to Minneapolis to undergo tests -- one pair of identical twins: Gerald Levy and Mark Newman were separated at birth and reared separately in middle-class Jewish homes in the New York area. they had physical and behavioral similarities as well as similar work history and the same roles as volunteer firefighters -- ongoing study: identical twins Scott and Mark Kelly are both astronauts. Scott spent a year on the International Space Station while Mark stayed on Earth. even several years after returning to Earth, researchers found that Scott's pattern of gene expression remained measurably different from Mark's

ethical issues in child-development research

-- ultimate responsibility lies with the researcher (have to anticipate potential risks that children may encounter, minimize such risks, and ensure that the benefits of the research outweigh any potential harm) -- children are more vulnerable to harm (small differences in children can lead to big differences in outcome as adults whereas those same differences in adults would be benign for their later development) -- immaturity affects understanding of results of participating -- children can not legally consent to participate in studies (parents or guardians agree to let their children participate and give their informed consent) -- children verbally assent to participate in studies and their verbal agreement is required even if their parent said yes -- children trust adults so there are issues with deception. we don't want children to fundamentally distrust adults (so good debriefing is necessary if there is deception): after the study, the researchers tell the children what the purpose of the study was (if they were looking at gestures, they tell the children after the study that they were looking at gestures) -- special ethical guidelines for kids -- risk vs. benefits ratio (weigh risks more heavily for studies involving children (plan to give participating children stickers, but IRB said you have to give stickers to every child)) -- example of unethical study: 1938 Dr. Wendell Johnson: hypothesized that children stutter because people constantly interrupt them. Research assistant went to the local orphanage to interrupt them. Children with stutters experienced worsening stuttering, and children without stutters developed them. -- protection from harm -- Society for Research on Child Development: be sure that the research does not harm children physically or psychologically, obtain informed consent for participating in the research (preferably in writing) from parents or other responsible adults and also from children if they are old enough that the research can be explained to them, preserve anonymity and do not use information for purposes other than that for which permission was given, discuss with parents or guardians any discoveries important for the child's welfare, try to counteract any unforeseen negative consequences, correct any inaccurate impressions that the child may develop in the course of the study

brain development: the importance of experience

-- use it or lose it: the more often a synapse is activated, the stronger the connection between the neurons involved. neurons that fire together wire together. if the synapse is rarely active, the axon of one neuron withdraws and the dendritic spine of the other is pruned away -- plasticity: capacity of the brain to be affected by experience (evolutionary to make less information be needed to be encoded in the genes). children's brains are more plastic than adults' brains so children who suffer from brain damage have a better chance of recovering lost function -- experience-expectant plasticity: general experiences that almost all infants have just by virtue of being human. species-typical; how a species evolves (eg. infants experienced patterned visual stimulation, voices and other sounds, movement and manipulation, etc. throughout human evolution). fewer genes need to be dedicated to normal development but there is heightened vulnerability. if the experience the developing brain expects does not occur, development may be compromised. the longer a cataract remains in place after birth, the more impaired the child's visual acuity will be once it is removed (visual cortex gets recruited by the auditory system). deaf newborns' auditory systems are co-opted by visual cortex (cross-modal reorganization). during sensitive time periods, the human brain is especially sensitive to specific external stimuli (neural organization that occurs or does not occur during sensitive periods is typically irreversible) -- experience expectant: brain is being shaped by expected experiences, expected at particular times and with expected intensity (premature babies should get less stimulation because the brain is expecting less stimulation; baby born with a cataract is not getting enough stimulation so they patch the non-damaged eye that one had already gotten specialization of function from being healthy and unobstructed at birth) -- phantom limb: a cure for unpleasant clenching of phantom hand is to have someone with an amputee clench and unclench their hand on their non-amputated limb in front of a mirror to trick the brain into thinking their amputated arm's hand is unclenched -- experience-dependent plasticity: specific, idiosyncratic experiences that children have as a result of their particular life circumstances. research with musicians: some body parts are trained more intensely than others. adults who play wind instruments have thicker lip-related cortical areas -- experience dependent: brain is shaped by experiences specific to the individual (sports, instrument-playing affect your brain differently depending on when you start)

theme #5: socio-cultural context

how bigger-picture social structures impact development, the features of development constant no matter the culture/circumstance, interactions between socio-cultural context and other features, whether the theories of development we have are applicable to other cultures -- physical and social environments (most important, also include institutions that influence children's lives), in a particular culture (values, attitudes, beliefs, and traditions), under particular economic circumstances (and technological advancement), at a particular time in history (laws and political structure) -- US childcare for toddlers and preschoolers: historical (50 years ago, far fewer children attended childcares), economic (more opportunities for women to work outside the home), cultural beliefs (childcare outside the home does not harm children), cultural values (women should be able to work outside the home even if they have young children) -- Urie Bronfenbrenner 1969 bioecological model -- cross-cultural comparisons (example: sleeping arrangements) -- in the US, newborn infants sleep in their parents' bedroom. when they are 2 to 6 months old, parents usually move them to another bedroom. in other societies like in Italy, Japan, and South Korea, young children almost always sleep in the same bed as their mother for the first few years and somewhat older children also sleep in the same room as their mother -- Morelli and colleagues 1992 interviewed middle-class mothers in Salt Lake City, Utah and in rural mayan families in Guatemala. in the US, as the children grew out of infancy, the nightly separation of child and parents became a complex ritual with activities intended to comfort the child like telling stories, reading children's books, singing songs, etc. also, about half the children were reported as taking a comfort objects, such as a blanket or teddy bear, to bed with them. mayan mothers said their children slept in the same bed with them until 2 or 3 years old and continued to sleep in the same room with them for years thereafter. the children usually went to sleep at the same time as their parents, and there were no reports of bedtime rituals and almost no reports of comfort objects. mayan cultures prize interdependence among people and developing a good parent-child relationship through their sleeping arrangements. they expressed shock and pity when told that infants in the US typically sleep separately from their parents. US culture prizes independence and self-reliance. -- all aspects of children's lives in multicultural societies vary with ethnicity, race, and SES (SES has a particularly large influence). in 2017, 18% of US families with children had incomes below the poverty line, defined as 50% of the median family income (in that year, $25,283 for a family of four with one adult and three children). 12,800,000 children grew up in poverty. poverty rates are especially high in Black and Hispanic families and in families headed by single mothers. also twice as high as their counterpart among the 25% of children who are immigrants or living with immigrant parents -- children from impoverished families: in infancy, they are more likely to have serious health problems. beginning at age 3 and continuing through at least age 20, their brains have less surface area, especially in areas that support spoken language, reading, and spatial skills. throughout childhood and adolescence, they tend to have more emotional problems, smaller vocabularies, lower IQs, and lower math and reading scores on standardized achievement tests. in adolescence, they are more likely to have a baby or drop out of school. they are more likely to live in dangerous neighborhoods, attend inferior day-care centers and schools, and be exposed to high levels of water and air pollution. they are more likely to grow up in single-parent homes or be raised by neither biological parent. accumulation of these disadvantages is called cumulative risk (greatest obstacle for poor children) -- resilient children (like those in Kauai in Werner's study) are more likely to have positive personal qualities (high intelligence, easygoing personality, optimistic outlook on the future), a close relationship with at least one parent, and a close relationship with at least one adult other than their parents. -- WEIRD (western, educated, industrialized, rich, democratic) -- susan goodall's research about deaf children -- whether the research methods we use are appropriate across cultures (pattern recognition task with a sequence completion question (only 12.5% of children correctly completed the pattern in Zambia on paper; but a ⅓ of children could complete the task when they had 3 dimensional objects; they did not have experience with 2 dimensional objects))

the concept of the active child refers to ______

how children contribute to their own development

what intervention program, involving direct skin-to-skin contact, are parents of low-birth-weight infants encouraged to use to support development and promote survival?

kangaroo care

Which type of design is used to study developmental change as it is occurring by observing participants numerous times over a relatively short span of time?

microgenetic

which of the senses is the least active while the fetus is in the womb?

sight

what is a characteristic of non-rapid eye movement (non-REM) sleep?

slow brain waves

studies have shown that children's testimony is usually accurate when which of the following conditions are met?

the interviewer does not ask leading questions

In the context of mechanisms of developmental change, the study of the development of "effortful attention" provides insights into _____

the role of brain activity, genes, and learning experiences

how do we study development?

what changes (describe) and why do those changes occur

what are the three domains of developmental psychology?

biological/physical: body size, body proportions, brain development and center of gravity (babies' center of gravity is in their heads because it is 1/3 of their bodies, things closer to your trunk/torso mature faster in a head-to-tail process, some of the first things infants learn to do is control their heads, ability to interact with objects and people comes from motor development and perceptual skills) cognitive: intelligence, language, problem solving, attention, imagination, concept development, working memory (digit span is at 2) in average five-year-old is not good social/emotional: relationships with other people, parenting, emotions that play a fundamental social role in life and communicate, moral reasoning, gender all three happen in the same people and interact

the Matthew effect chapter in The Outliers

-- Canadian psychologist Roger Barnsley noticed that the birth months of hockey players were all the same (mostly January, then February, and then March) -- in any elite group of hockey players, 40% will be born between January and March, 30% between April and June, 20% between July and September, and 10% between October and December -- Canadian age eligibility cutoff for hockey is January 1 so a player born on January 2 can be playing against players who are almost a whole year younger. 12-month gap has an enormous difference in physical maturity in preadolescence -- coaches recruit for rep squads when the players are 9 or 10 and most likely to view the oldest players as the biggest and most well-coordinated. students get picked for rep squads, and then get better coaching, better teammates, more playing (more games and more frequent practicing). at age 13 or 14, the older players are now actually better instead of just older -- skewed age distributions exist whenever there is selecting, streaming, and differentiated experience -- age cutoff for baseball in US is July 31. more Major League Baseball players are born in August than any other month -- European cutoff for football is September 1, which had the same effect -- international junior soccer cutoff is January 1 -- age cutoffs for kindergarten make younger children experience patterns of underachievement and discouragement when comparing themselves to older children. Kelly Bedard and Elizabeth Dhuey found that older children scored between 4 and 12 percentile points better on the TIMSS. teachers confuse maturity with ability and put older children in gifted programs/advanced groups. persists into four-year universities with young students of each class represented at 11.6%. Denmark doesn't let gifted program or advanced group selection occur until age 10 to combat the skewed age distribution -- Barnsley also found that students who attempt su**1d3 are more likely to be born in the second half of the school year -- those who are successful are most likely to be given special opportunities that lead to further success

sociocultural theories: view of children's nature

-- Russian psychologist Lev Vygotsky. Vygotsky portrays children as social learners, intertwined with other people who help them gain skills and understanding. Vygotsky viewed children as intent on participating in activities that are prevalent in the specific time and place in which they live. Vygotsky emphasized gradual continuous changes. Vygotsky viewed the relation between language and thought as intertwined (thought is internalized speech originating in statements that other people make to children). internalizing speech: first, children's behavior is controlled by other people's statements. then, children's behavior is controlled by their own private speech. finally, their behavior is controlled by internalized private speech (thought) in which they silently tell themselves what to do (transition between second and third phases involves whispers or silent lip movement). private speech is most evident between ages 4 and 6 although older children and adults also use it on challenging tasks -- children as teachers and learners: Michael Tomasello 2014 emphasized inclination to teach others of our species (emerges early on: even 1-year-olds point to and name objects to call other people's attention to what they themselves find interesting) and inclination to attend to and learn from such teaching -- children as social learners, who gradually become full participants in their culture through interactions with other people and with the broader social environment of institutions, skills, attitudes, and values -- children as products of their culture: processes are the same in all societies while the content that children learn varies greatly from culture to culture. study of analogical problem solving (where experience with previously encountered problems is applied to new ones) by Chen, Mo, and Honomichl 2004 asked students attending US and Chinese universities to solve a problem requiring a solution analogous to Hansel and Gretel's trail and another problem requiring a solution from a Chinese fairy tale. problem-solving strategy success was dependent on cultural familiarity with the story

Piaget's stages of cognitive development: preoperational stage

-- cheat sheet: yes symbolic, not logical, not abstract -- preoperational (2-7 years): mental representations become more complex (semiotic function: use a word to represent another thing), piaget said thought was fundamentally linguistic and until you can speak, you can't engage with thinking, sociodramatic play (let's pretend that it's school and you're the teacher and I'm the student: taking on roles), some things represent other things out in the world (a map represents a three-dimensional place; video example: 2.5 year old charlotte watches as the researcher hides little Snoopy in the miniature replica of the bigger room but could not find big Snoopy in the actual room; 3 year old Marielle found big Snoopy and little Snoopy), egocentrism of thought (inability to take someone else's perspective effectively or understand what someone else says; three mountains task where you can only see certain things like a church or lake from certain perspectives and the child will say the doll on the opposite side of the mountain sees exactly what they themselves see), primacy of perception (how things look; dye a skunk to look like it's a cat and the child will think it's a cat, though later research found flaws in this), centration (when there's more than one relevant dimension, you're focusing on only one dimension; fail conservation tasks; reversibility (if I take what I see in a glass and pour it back into where it came from, it would be the same), lack of hierarchical classification (can't see a dog as both a dog and an animal at the same time or a beagle as both a beagle and a dog at the same time), example: five-year-old who was reading Harry Potter on her own could not succeed at conservation tasks; when kids learn conservation tasks, they tend to get conservation-of-number first because they're actively counting; example of preoperational thought: researcher phil had children start a categorization game by shape or color and then switched the rules, and the children kept playing by the first game's rules; by the time you're 7 or 8 regardless of whether you went to preschool, you'll master these levels of cognition; if you directly teach conservation-of-volume, the child can learn that task earlier but won't apply it to the other conservation tasks; animistic thinking (everything has human feelings, reactions, and emotions; example: friend babysat her granddaughter who wanted to play make-believe Mary Poppins and her two stuffed animals with their own names were reassigned names; grand daughter said her grandmother hurt her stuffed animals' feelings by calling it by the wrong name); thinking things is as bad as doing them (magical thinking; example: nephew thinks the box being too heavy for the tooth fairy to open is why the tooth fairy didn't visit) -- thought not yet logical, mental representation (semiotic function, language and thought, make-believe play like sociodramatic play, symbol-real world relations like dual representation) -- thought: egocentrism, primacy of perception (appearance vs. reality), centration, inability to conserve (conservation and reversibility), lack of hierarchical classification, animistic thinking, magical thinking (can affect from a distance through actions, thoughts have a causal force) -- ages 2 to 7 years, toddlers and preschoolers become able to represent their experiences in language and mental imagery, which allows them to remember the experiences for longer periods and to form more sophisticated concepts. however, young infants are unable to perform certain mental operations like considering multiple dimensions simultaneously (conservation-of-liquid-quantity problem with tall and short glasses) -- foremost acquisition: symbolic representation or the use of one object, word, or thought to stand for another (forming personal symbols is common among 3- to 5-year-olds; usually objects toddlers and preschoolers use physically resemble what they represent; as children develop, they rely less on self-generated symbols and more conventional ones; capabilities evident in the growth of drawing) -- most notable weaknesses: egocentrism and centration -- egocentrism, perceiving the world solely from one's own point of view (preschoolers' difficulty in taking other people's spatial perspectives; Piaget and Inhelder 1956/1977 had 4-year-olds sit at a table in front of a model of three mountains of different sizes and asked them to identify which of several photographs showed what a doll would see if it were sitting on chairs at various locations around the table. most 4-year-olds can't do this; also in communication as preschoolers often talk right past each other; early sign of progress away from egocentrism is verbal quarrels because it means children are paying attention to the differing perspective) -- centration, focus on a single, perceptually striking feature of an object or event to the exclusion of other relevant features (approaches to balance-scale problems: 5- and 6-year-olds will center the amount of weight on each side, ignore the distance of the weights from the fulcrum, and say that whichever side has more weight will go down; conservation concept with conservation of liquid quantity, conservation of solid quantity, and conservation of number where 4- and 5-year-olds say the amounts are not the same)

Piaget's stages of cognitive development: concrete operational stage

-- cheat sheet: yes symbolic, yes logical, not abstract -- concrete operational stage (7-11 years): sensory evidence needed to help, problems can't have too many steps, they don't take a step back to decide if they said the correct answer/gradual acquisition of cognition is called horizontal decalage -- logical reasoning but limited to concrete problems, here & now, problems that are not too complex, often leave out steps/fail to fully complete the problem, failure to consider all possible solutions, success on conservation problems -- thought: horizontal decalage, gradual mastery of logical concepts with number conservation, then volume, then mass; concrete, not abstract -- ages 7 to 12 years, children can reason logically about concrete objects and events, can solve the conservation-of-liquid-quantity problem and other conservation concept problems (most 8-year-olds solve all of them) because they understand that events can be influenced by multiple factors, can solve balance-scale problem by considering distance and weight, cannot think in purely abstract terms or generate systematic scientific experiments to test their beliefs (limited to concrete situations; thinking systematically and reasoning about hypothetical situations remain difficult) -- limitations evident in the types of experiments children perform to solve the pendulum problem (children are given a frame, a set of strings of varying lengths with a loop at each end, and a set of metal weights of varying weights. task is to perform experiments that indicate which factor or factors influence the amount of time it takes the pendulum to swing through a complete arc. most children begin believing relative heaviness of weights is the most or only important one. they design biased experiments where multiple variables are changed

Piaget's stages of cognitive development: formal operational stage

-- cheat sheet: yes symbolic, yes logical, yes abstract -- formal operational (ages 11 and up): can create and operate on mental models (can picture two glasses of water in mind; can answer conservation problems without actually doing them; can answer "if this were to happen, I would do this" without ever experiencing the hypothetical situation), pendulum experiment (systematic changing of one variable at a time) -- abstract, scientific thought (if-then reasoning, can create and test hypotheses, evaluate hypothetical outcomes, reason about past and future) -- ages 12 years and beyond, adolescents and adults can think deeply not only about concrete events but also about abstractions and purely hypothetical situations, can also perform systematic scientific experiments and draw appropriate conclusions from them even when the conclusions differ from their prior beliefs -- difference from concrete operational stage is approach to pendulum problem (they test the effect of each variable systematically; make all variables constant other than variable of interest) -- not universal: not all adolescents or adults reach it -- those who do can think about alternative ways the world could be and how they could live their lives

information-processing theories: the development of problem solving

-- children as active problem solvers -- overlapping waves theory: individual children usually use a variety of approaches to solve problems (arithmetic, time-telling, reading, spelling, scientific experimentation, biological understanding, tool use, and memory recall). most 5-year-olds use at least three different strategies on repeated trials of the conservation-of-number problem. strategy 1 is the simplest strategy and strategy 5 the hardest and the usage of them peaks at different ages. at the youngest age, children usually use Strat 1 but they sometimes use Strat 2 or 4. by the middle of the age range, children have added Strats 3 and 5 and have almost stopped using Strat 1. example with single-digit addition: during kindergarten and first few years of elementary school, children's knowledge of these arithmetic problems increases greatly as they discover new strategies like counting-on, as they have faster and more accurate execution of prior known strategies, and as they choose among strategies increasingly adaptively -- early differences in numerical knowledge among children from different economic backgrounds (factors: playing board games like Chutes/Snakes and Ladders because Ramani and Siegler 2008 had 4- and 5-year-olds from impoverished families play a number-board game or a color-board game. children in first condition showed lasting improved knowledge of 1-10 with counting, reading numbers, comparing magnitudes, and estimating locations of numbers on a number line. another study showed that the 1-10 board game also improved preschoolers' ability to answer arithmetic problems -- planning is difficult for young children because it requires inhibiting the desire to solve the problem immediately in favor of first trying to choose the best strategy and because they tend to be overly optimistic about their abilities and believe they can solve problems without planning. 6-year-olds who overestimate their physical abilities have more accidents than peers who evaluate their abilities more realistically, presumably because their overconfidence leads to them not planning how to avoid potential dangers. maturation of the prefrontal cortex and experiences that reduce overoptimism lead to increases in the frequency and quality of planning. improvements in planning take a long time to become routine. in dangerous situations, 12-year-olds remain more likely than adults not to plan and to take risks

fetal learning

-- fetus learns from its experiences in the last 3 months of pregnancy (after the central nervous system is adequately developed to support learning) -- infants remembered specific prenatal auditory experiences that were presented via audio speakers adjacent to the mother's abdomen (like repetitions of a single nonsense word or a melody) -- studies of habituation: fetuses grow bored if a stimulus is repeated over and over again (stimulus becomes boring only if it is remembered). fetuses as young as 30 weeks gestation show habituation to both visual and auditory stimuli -- Kisilevsky and colleagues 2003 tested term fetuses (half listened to a recording of their mother reading a poem, played through speakers placed on the mother's abdomen while the other half listened to recordings of the poem read by another women. fetal heart rate increased in the former condition but decreased in the latter condition so that arousal means fetuses must be learning and remembering the sound of their mother's voice -- newborns still prefer their mother's voice over the voice of another women. they also prefer to listen to the language they heard in the womb over another language. they also remember the sounds of specific stories heard in the womb. they also remember the scent of amniotic fluid, turning toward their own amniotic scent and preferring scents reflecting flavors their mother ate while she was pregnant -- long-lasting taste preferences: a study where pregnant women drank carrot juice for three weeks near the end of their pregnancy. when tested at around 5.5 months of age, their babies reacted more positively to cereal prepared with carrot juice than cereal prepared with water -- fetal brain is unlikely to be sufficiently developed to process much about language meaning. the liquid environment in the womb filters out detailed speech and music sounds, leaving only pitch contours and rhythmic patterns so the fetus learns general sounds but not specific content

dynamic-systems theories: overview

-- focus on how change occurs over time in complex systems, soft assembly (self-organization that integrates across cognition, action, and what's available in the environment), strategy variation and selection -- emphasize the development of actions in complex systems over varying time periods (fractions of seconds, seconds, minutes, hours, days, months, and years) -- dynamic-systems research has shown that improved reached allows infants to categorize objects in more advanced ways. also, the onset of crawling changes infants' relationships with family members who may be thrilled to see their baby attain this milestone but less thrilled about the increased vigilance and rearrangement of living spaces needed -- Esther Thelen and colleagues 1993 repeatedly observed the reaching efforts of four infants during their first year. because of individual differences in the infants' physiology, activity level, arousal, motivation, and experience, each child faced different challenges in mastering reaching. onset of adept reaching varies greatly among infants. for each infant, the development of reaching showed periods of rapid change, periods without much change, and even regressions in performance. some infants had discontinuous improvements while others had continuous ones. some infants needed to damp down overly vigorous movements while others needed to reach more vigorously -- development as a process of constant change. thought and action change from moment to moment in response to the current situation, the child's immediate past history, and the child's longer-term history in similar situations -- child as well-integrated system (subsystems work together to determine behavior: perception, action, attention, memory, language, and social interaction). eg. object permanence influenced by perception, attention, motor skills, etc.

Piaget's Theory of Cognitive Development (view of children's nature)

-- fundamental assumption: children are mentally active from the moment of birth and their mental and physical activity both contribute greatly to their development -- constructivist approach because it depicts children as constructing knowledge for themselves in response to their experiences -- three of the most important of children's constructive processes: generating hypotheses, performing experiments, and drawing conclusions from their observations -- dominant metaphor: child as scientist (example: his son, Laurent, dropping the toy from different places and seeing what happens) -- children learn many important lessons on their own instead of depending on instruction from others -- children are intrinsically motivated to learn and do not need rewards from other people to do so -- nature of change: discontinuous and qualitative

sociocultural theories: central developmental issues

-- intersubjectivity (foundation of human cognitive development is our ability to establish it), the mutual understanding that people share during communication. effective communication requires participants to focus on the same topic and each other's reaction to the information being communicated. by age 6 months, infants can learn novel behaviors by attending to another person's behavior. older preschoolers and elementary-schoolers are more likely to reach agreement with peers on game rules and each child's role in it. increasing ability to teach and learn from one another -- joint attention: infants and their social partners intentionally focus on a common referent in the external environment. around their first birthday, infants increasingly look toward objects that are the targets of their social partners' gaze even if the partner is not acting on the objects. around the same age, infants begin to actively direct a partner's attention toward objects that they themselves find interesting. example: the degree to which infants follow other people's gaze when they are teaching them a new word predicts the infant's later vocabulary development and language development. infants between 8 and 18 months of age more often attend to, imitate, and learn new labels for objects from adults whom they see pursuing goals competently than from adults they see acting incompetently -- educational applications: change culture of schools to aim to foster deep understanding, cooperation, and enthusiasm for learning more. Ann Brown's 1997 community-of-learners program of 6- to 12-year-olds, most of them Black children in Boston and Oakland, California. main curriculum is projects that require research on some large topic. class divides into small groups, each of which focuses on a particular aspect of the topic. at the end of 10 weeks, new groups are formed, and children are asked to solve a problem whose solution incorporates parts of all the topics studied. jigsaw approach where all children's contributions are essential for the new group to succeed. this helped children become increasingly adept at constructing high-quality solutions to the problems they tried to solve. also, they learned general skills like identifying key questions and comparing alternative solutions to a problem and mutual respect and responsibility

educational application of Piaget's theory

-- investigation into how to promote children's understanding of speed -- "when a race horse travels around a circular track, do its right and left sides move at the same speed?" they do not. side toward the outside of the track is going slightly faster -- iris levin and her colleagues devised a way for children to actively experience how different parts of a single object can move at different speeds (7-foot-long metal bar was walked around a pivot by 6th graders who held onto it; on two of the walks, they held the bar near the pivot; on the last two, they held it at the end; dramatic different speeds required for holding onto the bar)

Piaget's legacy

-- limitations of piaget: children are not as egocentric as he thought they were (children are more empathetic), consistent underestimating because children were understanding more, he laid good groundwork but we know more, simplify the task (eg. turn off the lights and children will solve the A-not-B task); even at five years old, children who work as street vendors can solve monetary conservation-of-number problems; if you make the task more meaningful (eg. let them take home what they count), their action of taking home what has more shows they understand the quantity even if their words point to otherwise -- performance not as limited as suggested, simplify the task (reduce action demands, use looking rather than reaching, reduce memory demands, make the task more familiar), change the wording (focus on relevant issues, don't use strange questions), don't ask repeated questions, thinking not as consistent as "stages" suggest, all adults don't reach formal operations, understates social components of cognitive development, exceptionally good at describing behavior, not as good at inference about underlying processes, Piaget's legacy -- piaget critique: thinking not as consistent as "stages" suggest because people fail adult conservation problems like: same amount of trinkets in both mugs and equal replacement each time (both containers have to have the same amount of the "other" color); questions about whether all adults reach formal operations; only talks about the child constructing their own development; some children are partial conservers (if you do the same conservation task multiple times in the same day, the children may give different answers and flip-flop between correct and incorrect answers) -- his legacy: all later theories have to account for his observations; many later theories are reactionary to his -- weaknesses: -- Piaget's theory is vague about the mechanisms that give rise to children's thinking and that produce cognitive growth (how assimilation, accommodation, and equilibration occur is unclear) -- infants and young children are more cognitively competent than Piaget realized (he employed fairly difficult tests; missed their earliest knowledge of these concepts; his test of object permanence required they reach for the hidden object after a delay, but infants look at the right hiding place immediately after the object has disappeared by 3 months of age) -- Piaget's theory understates the contribution of the social world to cognitive development -- stage model depicts children's thinking as being more consistent than it is (most children succeed on conservation-of-number problems by age 6 but most do not succeed on conservation-of-solid quantity until about age 8)

dynamic-systems theories: view of children's nature

-- newest of the types of theories -- motivators of development: emphasize that from infancy onward, children are internally motivated to learn about the world around them and to explore and expand their own capabilities. children persist in practicing new skills even when they possess more efficient well-practiced skills. 1-year-olds try to walk down ramps even though crawling would get them down more quickly and without the risk of falling. infants' interest in the social world as a crucial motivator. even newborns prefer attending to the sounds, movements, and features of the human face. by 10 to 12 months, infants are motivated to direct the attention of others to objects and events they themselves find interesting. motivators: observing other people, imitating their actions, and attracting their attention -- centrality of action: emphasis on how children's actions shape their development throughout life. infants' own reaching for objects helps them infer the goals of other people's reaches, and infants who can skillfully reach are more likely to look at the probable target of another person's reaching. infants were given velcro mittens to grab and explore velcro-covered objects they otherwise couldn't pick up. after two weeks of successfully grabbing them, infants showed a greater ability to grab and explore non-velcroed objects without the mittens. categorization study encouraged children to move an object up or down and side to side and it led to their categorizing it as one of a group of objects easiest to move in one way. when children state an incorrect name for an object, it impairs their future attempts to learn the object's correct name

information-processing theories: two notable characteristics

-- precise specification of the complex processes involved in children's thinking (David Klahr's task analysis: identification of goals needed to perform the task, obstacles that prevent immediate realization of the goals, prior knowledge relevant to goal achievement, and potential strategies for reaching the desired outcome). class of theories focused on the structure of the cognitive system and the mental activities used to deploy attention and memory to solve problems -- Simon and Klahr 1995 created computer simulations of the knowledge and mental process that led young children to fail on conservation problems and of the knowledge and mental processes that allowed older children to succeed on them (other computer simulations: on object permanence, word learning, working memory, and problem solving) -- second feature: an emphasis on thinking as a process that occurs over time (eg. a single behavior as a reflection of an extended sequence of fast, unconscious mental operations). these theories identify the mental operations, the order in which they are executed, and how increasing speed and accuracy of them lead to cognitive growth -- cognitive development occurs incrementally and continuously

dynamic-systems theories: central developmental issues

-- self-organization: integrating attention, memory, emotions, and actions as needed to adapt to a continuously changing environment. called soft assembly because the components and their organization change from moment to moment and situation to situation. studies of A-not-B error that 8- to 12-month-olds typically make reflects combined influence of the strength of habit, memory demands, and current focus of attention. Smith and colleagues 1999 hypothesized that babies' previous reaches toward A produce a habit so the more often babies had found an object in one location, the more likely they would be to reach there again after it was moved. increasing memory demands by making infants wait for 3 seconds increased likelihood of the error. attention influences: tapping one of the locations as the infant is about to reach usually results in their reaching to the tapped location -- mechanisms of change: mechanisms of variation and selection analogous to those that produce biological evolution. variation refers to the use of different behaviors to pursue the same goal (to descend a ramp, a 1-year-old will sometimes walk, sometimes crawl, sometimes belly slide, sometimes sit and feet-first slide). selection involves increasingly frequent choice of behaviors that are effective in meeting goals and decreasing use of less effective behaviors (when children first learn to walk, they often are too optimistic about ability to walk down ramps and frequently fall but after a few months, they more accurately judge the steepness of ramps and choose an appropriate strategy). approaches for selection: relative success of each option, efficiency, novelty -- educational applications: premature babies with low birth weight have slower emergence of reaching. Heathcock, Long, and Galloway 2008 applied some infants' slowness to initiate arm activity impeding their reaching development and how providing young infants with the velcro mittens and objects helps them grab barehanded. researchers had caregivers encourage arm movements by tying a bell to the infants' wrists and giving them velcro mittens at home and in the lab. over 8 weeks, the reaching improved

information-processing theories: view of children's nature

-- the child as a limited-capacity processing system: cognitive development arises from children gradually surmounting their processing limitations (limited working memory capacity, processing speed, and knowledge of useful strategies and content). through learning and maturation of brain structures, children expand the amounts of information they can process at one time, process information faster, and acquire new strategies and knowledge. these changes yield improvement in problem solving, memory, and other cognitive functions -- the child as problem solver: children are active problem solvers, and problem solving involves strategies for overcoming obstacles and attaining goals. children's cognitive flexibility helps them attain their goals (even young children show great ingenuity in surmounting the obstacles imposed by their parents, the physical environment, and their own lack of knowledge)

early philosophers' views of children's development

-- usually based their conclusions on general beliefs and informal observations of only a few children -- plato and Aristotle (4th century BC): interested in how children are influenced by their nature and by the nurture they receive, believed the long-term welfare of society depended on the proper raising of children. careful upbringing was essential because children's basic nature would lead to their becoming rebellious and unruly -- plato viewed the rearing of boys as a particular challenge and emphasized self-control and discipline as educational goals -- Aristotle emphasized fitting child rearing to the needs of the individual child -- plato believed children have innate knowledge (eg. children are born with a concept of animal that, from birth onward, automatically allows them to recognize dogs, cats, and other creatures they encounter as animals) -- Aristotle believed all knowledge comes from experience and the mind of an infant is blank -- John locke (British, 1632-1704) and jean-jacques Rousseau (French, 1712-1778) emphasized how parents and society in general can best promote children's development -- Locke viewed children as a blank slate (development largely reflects nurture received), emphasized growth of character as the most important goal of child rearing through parents setting good examples of honesty, stability, and gentleness and avoiding indulging the child but relaxing authority as fast as they can (advocated discipline before freedom though) -- Rousseau advocated maximum freedom from the beginning, claiming children learn primarily from their spontaneous interactions instead of through parental or educational instruction, and he argued that children should not receive formal education until age 12 or the age of reason (before, they should be free to explore whatever interests them) -- kagan (2000) concluded that children have an innate moral sense encompassing five abilities that even our closest primate relatives lack including the ability to infer the thoughts and feelings of others, to apply the concepts of good and bad to one's own behavior, to reflect on past actions, to understand that negative consequences could have been avoided, and to understand one's own and others' motives and emotions -- developmental psychology only emerged as formal discipline 100 years ago (people didn't have a lot of time or energy to wonder how children are different from adults) -- normative development (milestones like what should the average ___- year-old be able to do came from this movement, which was started in the early twentieth century by Arnold gesell and G. Stanley hall) -- intellectual testing (Binet made a standardized IQ test because he was asked by the French government) -- changes in family systems (children were a necessity in the past for family businesses but now they are luxuries and a choice, children had adult-like lifestyles and were seen as smaller, less effective adults), social fabric, political climate, intellectual climate

according to Piaget, development is both continuous and discontinuous. which of the following aspects of piagetian theory would be considered a source of discontinuity?

invariant stages

which describes an infant who is most likely suffering from colic?

Vivian cries for several hours a day for unexplained reasons

Thinking that does not factor in the viewpoints of others is known as

egocentrism

Rats that are raised in cages with toys develop more dendritic spines and more synapses per neuron than rats raised in cages without this stimulation. The different responses in the brains of these two groups of rats provide an example of which biological process?

experience-dependent plasticity

the genetic material an individual inherits is called the ____

genotype

Five-year-old Marcus is learning gymnastics. He's having trouble on the balance beam, so his teacher assists by holding his hand as he walks across. This interaction can be described as

guided participation

According to the Society for Research in Child Development, which of the following is not a stated ethical principle for conducting research with children?

information about the child uncovered through the course of the study must not be revealed to the parent or guardian, regardless of its importance for that child's welfare

Jamal is walking with his mother. He taps her on the arm, points to an animal, and says "Doggie!" This is an example of:

joint attention

according to information-processing theories, the ability to encode, story, and retrieve information is referred to as

memory

epigenetic effects have been demonstrated in studies with rats in which the absence of specific grooming behaviors from the mother results in reduced levels of glucocorticoid receptor gene activity in her pups. this processing of gene expression silencing is known as

methylation

Traits such as aggression and shyness are the result of the contributions of a complex combination of genes. These traits are examples of which process?

polygenetic inheritance

Piaget's theory of cognitive development is comprised of four invariant stages from birth to adolescence. which of the following is the correct chronology of these stages?

sensorimotor, pre operational, concrete operational, and formal operational

an individual's genetic sex is determined by

the sex chromosomes contributed by the father

issue of whether playing violent video games makes children and adolescents more aggressive

-- Ferguson (2015) reviewed 101 studies using a meta-analysis that indicated that the effect of playing violent video games on children's and adolescents' aggression was minimal (did appear to increase aggressive behavior by a small amount), which contradicted claims that these games are a major cause of aggression

early social reform movements devoted to improving children's lives

-- Industrial Revolution of the 1700s, 1800s, and early 1900s: many children as young as 5 and 6 years in Europe and the US worked as poorly paid laborers up to 12 hours a day in factories or mines with few if any legal protections and often in extremely hazardous conditions -- earl of Shaftesbury before the British House of Commons in 1843 gave a speech about the narrow tunnels where children dug out coal, and this speech brought on a law forbidding employment of children younger than 10

common research methods in developmental psychology

-- data collection: -- interviews inexpensively ask parents or children for in-depth data (clinical doesn't have a specific line of questioning and instead has general categories of information to seek out while structured interviews, with their sets of predetermined questions administered to participants, ask the same questions of everyone) -- structured interviews: when the goal is to collect self-reports or reveal children's subjective experiences on the same topics from everyone being studied -- with young children, the questions are usually presented orally. however, with children of reading age, printed questionnaires (a method that allows researchers to gather information from a large number of participants simultaneously by presenting them a uniform set of printed questions) are usually used (both oral interviews and printed questionnaires provide a quick and straightforward way for researchers to learn about children's feelings, beliefs, and behaviors) -- clinical interview: useful for obtaining in-depth information about an individual child because the interviewer begins with a set of prepared questions but if the child says something intriguing, the interviewer can depart from the script to follow up on the child's lead (example: 10-year-old Bobby was assessed for symptoms of depression. the interviewer asked him about school and got a response that Bobby viewed himself as bad at everything. the interviewer explored this further by asking what Bobby would wish for if three wishes could be granted and got more comments that aligned with symptoms of depression) -- disadvantages of interviews: answers are often biased (children avoid disclosing facts that show them in a bad light, misremember the way that events happened, can't predict future behavior accurately, and fail to understand their own motivations) -- observation (naturalistic's example is Gerald Patterson's 1982 study of family dynamics in "troubled" and "typical" families defined by the child's signs of behavior in which researchers observed dinnertime interactions where troubled families had more self-absorbed and less responsive parents and children responding to parental punishment with more aggression; structured involves setting up the situation (like asking a parent to ask their child to clean up the room)) -- disadvantages of naturalistic observation: naturally occurring contexts vary on many dimensions (difficult to know which aspects are most influential) and many behaviors of interest occur only occasionally in the everyday environment -- example of structured observation: Kochanska, Coy, and Murray 2001 had mothers bring their toddlers to a lab room with many especially attractive toys on a shelf and less attractive toys scattered around the room. the experimenters asked each mother to tell her child they could play with any of the toys except the ones on the shelf, and raters observed the children through a one-way mirror and classified them as complying wholeheartedly, grudgingly, or not at all. then, the experimenter asked the mother to leave the room and observed whether the child played with the forbidden toys. children who first complied wholeheartedly did not play with the forbidden toys for a longer time later and were more likely to comply with the mother's request to put away the many toys on the floor. when retested near their 4th birthday, they showed the same type of compliance -- advantages of structured: ensures all children being studied encounter identical situations (allows direct comparisons of different children's behavior in a given situation and, as in the research just discussed, also makes it possible to establish the generality of each child's behavior across different situations -- disadvantages of structured: does not provide as extensive information about individual children's subjective experience as do interviews not can it provide the open-ended everyday kind of data that naturalistic observation can yield -- research types: experiments, correlational studies (correlation does not imply causation), descriptive/observational studies do not involve variable manipulation, hard to draw generalizations from case studies, ethnography is becoming a preschool assistant teacher to study preschool settings (studying from the inside) -- correlational designs: determine whether children who differ in one variable also differ in predictable ways in other variables (number of hours per week children spend reading correlates highly with their reading-test scores; more obese children tend to exercise less) -- direction-of-causation problem and third-variable problem for correlations (correlation between children younger than 2 years sleeping with a nightlight and their later becoming nearsighted lead to an article concluding that light was harmful to visual development, which was wrong. the nearsighted children had nearsighted parents, who more often put nightlights in their infants' rooms) -- age, sex, race, and social class can not be manipulated or randomly assigned so they can only be studied in correlational studies -- reasonably large number of participants for experimental: 30 or more per group -- experimental control: ability of the researcher to determine the specific experiences that children in each group encounter during the study -- experimental design example: study tested whether playing TV shows (in the study, Jeopardy!) in the background while infants and toddlers play lowers the quality of that play. toddlers looked at it an average of only once per minute and only for a few seconds at a time, but it still reduced the length of play episodes and their focus on them -- disadvantages: less external validity because of artificial experimental situations in labs and cannot be used to study variables like age, sex, temperament, etc.

behavior genetics: molecular genetics research designs

-- examine specific DNA sequences to identify mechanisms that link genes and behavior -- have larger sample sizes than twin studies and include more diverse participants -- genome-wide association studies: recent study involved almost 80,000 adults and identified 18 different genomic regions (mostly those expressed in brain tissue) implicated in individual differences in intelligence -- genome-wide complex trait analysis: one study determined whether the effects of family SES on school achievement are genetically mediated and studied unrelated British children (genetic factors accounted for fully half of the correlation). in another study, researchers analyzed the DNA of children from7 to 12 years of age and uncovered evidence of genetic stability (the same genes are implicated in heritable aspects of intelligence across this age span) -- GWAS and GCTA studies of reading ability suggest lower heritability than twin studies -- genetically transmitted developmental disorders: Huntington disease (a fatal degenerative condition of the brain) is caused by one dominant gene, so is neurofibromatosis (a disorder in which nerve fibers develop tumors). a combination of severe speech, language, and motor difficulties that was first discovered in a particular family in England was traced to a single gene mutation (FOXP2) that acts in a dominant fashion. sickle-cell disease (which affects 1 of every 500 African Americans) is a painful recessive-gene disorder but individuals who are heterozygous have resistance to malaria -- X-linked inheritance examples: male-pattern baldness, red-green color blindness, fragile-X syndrome (mutations in the X chromosome and most common inherited form of intellectual disability), hemophilia, Duchenne muscular dystrophy -- polygenic inheritance: molecular genetics studies suggest that each gene has just a small effect on its own (examples: cancers, heart diseases, type 1 and 2 diabetes, asthma, schizophrenia, behavior disorders like ADHD and dyslexia) -- aneuploidy due to errors in germ-cell division that result in zygotes with more or fewer chromosomes. Down syndrome most commonly originates when a fertilized egg contains an extra copy of chromosome 21 (occurs in 1 of every 700 live births in the US. offspring of a 45-year-old woman has a 1 in 30 chance) -- gene anomalies: deletion of approximately 25 genes from a small section on chromosome 7 (relationship between number of deleted genes and resulting phenotype for this condition) causes Williams syndrome (impaired spatial and visual skills and language ability to a lesser degree; outgoing personalities and friendliness paired with anxiety and phobias) -- unidentified genetic basis: autism (currently between 500 and 1000 candidate genes associated with autism)

cognitive and behavioral flexibility

-- prolonged brain growth and extended immaturity allow humans to master the skills needed for living in complex and varied societies -- humans rely more heavily on learning and behavioral flexibility for survival than any other species, which is made possible by high degree of plasticity

brain development: neurons and the cortex

-- vast majority of your neurons are present at birth (most neurogenesis happens prenatally); more exercise leads to more neurogenesis and better synaptogenesis; neurons become specialized; cell body of a neuron is where there is summation of input; dendrites are the input system and clustered around the cell body; axon is the output system; synaptic vesicles in the axon terminal buttons that release neurotransmitters into the synapse after/when the neuron fires; myelin sheath made of schwann glial cells; neural signal jumps from one node of ranvier to the next; a spinal cord neuron might have an axon that is several feet long (for signals from toes to brain) while neurons in the retina of an eye will have short axons; synaptogenesis happens and causes a lot of density in the first few years of life (too many connections so pruning through "use it or lose it" principle that gets rid of connections that aren't useful and don't get activated or used); myelination or myelinization (add the myelin sheath to axons; sustained attention needs this; MS is a demyelinating disorder; really important) -- left and right brain hemispheres have four lobes each (occipital in the back is for vision, parietal is sense of touch and spatial skills, temporal is memory consolidation and auditory processing, frontal is executive function); left is language while right is spatial (facial recognition happens in the right); more plasticity earlier in life (if the left hemisphere is taken out early on, the right will take over language functioning) because synaptic connections aren't strong yet; the more synaptic connections you make early on, the less the cognitive decline; the more you mix things up, the more flexible your brain is -- more than 100 billion neurons in the brain, which constitute the gray matter of the brain -- some neurons have as many as 15,000 synaptic connections with other neurons -- glial cells function as neural stem and progenitor cells during prenatal brain development and some continue to do so into adulthood. when the brain is injured, some glial cels react by rapidly increasing in numbers, protecting the brain and potentially aiding in regeneration -- cerebral cortex constitutes 80% of the human brain. parts that are most enlarged compared with other species are the ones that grow the most as children develop. association areas between the major sensory and motor areas -- young infants use their right hemispheres more than their left to process faces, and their left hemispheres more than their right to process most aspects of speech -- electrophysiological recording: electrical recording obtained through the scalp are non-invasive and can even be used with very young infants. electroencephalographic (EEG) recordings of electrical activity generated by neurons are used to study the time course of neural events and brain/behavior relationships. event-related potentials (ERPs) detect changes in the brain's electrical activity that occur in response to the presentation of a particular stimulus. magnetoencephalography (MEG) detects magnetic fields generated by electrical currents in the brain; can be used to localize the origin of the electrical signals within the brain as well as their time course unlike EEG. in a recent MEG study, researchers recorded electrical signals from 7-month-olds as they were touched on either the hand or foot and as they watched someone else being touched on the hand or foot. the corresponding areas of somatosensory cortex were activated both times -- functional magnetic resonance imaging (fMRI) studies use an electromagnet to detect fluctuations in cerebral blood flow in different areas of the brain. most fMRI studies with children include practice sessions with a mock scanner to help children acclimate to the noise and close confinement of an MRI machine. when fMRI studies involve infants, they usually need to be asleep. however, one recent study successfully used fMRI to test awake infants on a visual processing task. diffusion tensor imaging, a variant of conventional MRI that uses the rate of water diffusion to model 3D spatial location, has been used to model white-matter development and myelination over the course of early postnatal development and to investigate atypical patterns of brain connectivity in populations including preterm infants and autistic toddlers. resting-state functional magnetic resonance imaging measures brain activity in the absence of any external stimuli or tasks and is appropriate for use with sleeping infants; its networks emerge early in development (some sensory networks are evident in full term newborns and others emerge over the first year of postnatal life) -- near-infrared spectroscopy: optical imaging technique that measures neural activity by detecting metabolic changes that lead to differential absorption of infrared light in brain tissue. the infrared light is transmitted to the brain, and its absorption is detected by means of an optical-fiber skullcap or headband. silent, noninvasive and does not require head stabilization so it is particularly promising for research with infants and young children. one use: simultaneous recording from adult-infant pairs to examine coupling of their brain responses (brain responses correlated when the two played together; uncorrelated when they were each interacting with other adults)

textbook overview of theories of cognitive development

-- we expect different language and problem solving from newborn versus toddler (don't expect much language production) versus adult -- individual differences example: Broaders' best friend doesn't like playing games that involve thinking while Broaders loves the NYT crossword and Wordle (both went to the same high school) -- nativism: -- you're a product of nature, development is the unfolding of predetermined map. Arnold Gesell: superficial experience believer, took twins who don't know how to climb stairs. One gets a low experience with stairs and the other is kept away. The one kept away catches up really quickly (skill was unfolding naturally). He was working on normative child study (children just moving through at their own predetermined pace). however: even a deprived situation is a situation so there is no absence of experience. core knowledge theorists: they are interested in what things seem to be default and built into genes in our brains as humans -- behaviorists (eg. Skinner, Watson): -- behavior is an amalgamation of conditioned responses -- thought it was all about the environment, they didn't think cognition and the brain is fair game to study because they couldn't directly see it (avoided internal constructs) -- reductionism: can take a relatively complex skill and break it down into simple pieces (eg. information processing theories), does not work for all psychological phenomena (how you do something and think about what you're doing changes as you develop expertise; chess experts only remember chess piece layouts if they are valid in terms of the game's rules; Skinner says behaviorism can account for language but Chomsky contradicted him; toddlers are way too good at language production to account for their minimal conditioning; some cognitive conceptions/ideas can't come from experience like drawing where the waterline is when a cup is tilted) -- parsimony: Occam's Razor, simplest explanation is the best, static learning mechanism -- cognitive development includes the growth of such diverse capabilities as perception, attention, language, problem solving, reasoning, memory, conceptual understanding, and intelligence -- five particularly influential theories: piagetian (nature and nurture, continuity/discontinuity, active child), information-processing (nature and nurture, mechanisms of change), core-knowledge (nature and nurture, continuity/discontinuity), sociocultural (nature and nurture, influence of the sociocultural context, mechanisms of change), and dynamic-systems (nature and nurture, the active child, mechanisms of change) -- the non-piaget four: attempts to overcome a major weakness of Piaget's approach (information-processing and precise characterizations of the mechanisms of change; core-knowledge and the surprisingly early knowledge and skills infants and young children show in areas of evolutionary importance; sociocultural and children's interactions with other people and cultural products; dynamic-systems and variability of children's thinking)

the first basic step in using the scientific method involves

choosing a question

which of the following is not a function of glial cells?

conduct electrical signals away from one neuron and to another

according to developmentalists, which of the following is true?

development is influenced by the joint workings of nature and nurture

In order to generalize her findings beyond the individuals who participated in her study, Dr. Liu needs to conduct additional research using participants from a variety of backgrounds. What quality of behavioral research is Dr. Liu addressing?

external validity

a twin-study design project reveals that the correlation between identical (MZ) twins on a given trait that is substantially higher than that between fraternal (DZ) twins. which of the following statements offers the most plausible explanation for the difference in how this trait is correlated in MZ twins compared with DZ twins?

genetic factors are substantially responsible for the difference in correlation

in recent decades, researchers have come to the conclusion that, after infancy, most developmental changes occur _____

gradually

which of the following responses would be consistent with the statement "high heritability does not imply immutability"?

intervention efforts can successfully influence the course of development related to an inherited trait

nativists' arguments vs. empiricists' arguments

nativists: argue that evolution has created many remarkable capabilities that are present even in early infancy such as understanding basic properties of physical objects, plants and animals, and other people empiricists: argued that infants possess general learning mechanisms that allow them to learn a great deal quote quickly, but infants and young children lack the specialized capabilities that nativists attribute to them

the physical, social, cultural, economic, and historical circumstances that make up a child's environment are known as the ______

sociocultural context

what does the multiple-risk model suggest about negative developmental outcomes?

the more risk factors that are present, the more likely and worse the potential outcomes will be

basic principle of child development based on the Romanian adoption study

the timing of experiences influences their effects. children were sufficiently flexible to overcome effects of the orphanage if the deprivation ended by age 6 months. the later the age of adoption, the longer the harmful effects lasted (rarely overcame completely)

importance of theories

theory: casual explanation of some phenomenon, frameworks for interpreting evidence, observed situation and assumptions underlying the theory (example: child might be nervous at first and then reach out and be social after a few weeks in school; might be caused by shy temperament, parenting, task management from focusing on one factor of the environment at a time) -- no grand unifying theory for development (instead they focus on specific topics) -- theories vary greatly on how they view developmental change, roles of nature and nurture, and what aspects of development they focus on -- theories guide research (constrain questions asked, constrain methods used, determine new directions, bias interpretations) and affect how you interpret data (eg. children develop unwanted behaviors... theory could be that delinquency comes from environment so the research studies will all look at environmental factors or theory could be that delinquency comes from biological predisposition so the research studies involve twin studies) -- theories make meaning of the data (eg. piaget articulated a theory based on his research; hall just put his research out there without coming up with a theory)

theme #6: individual differences

why children are so different in seemingly similar environments, whether similar or different mechanisms account for development across individuals (different: strategies to first steps), risk and resiliency factors (longitudinal study of children in Hawaii and how resiliency and at-risk aspects were developed (having even just one really, positively invested and interested adult in your life)), normative development issues -- example from class: Broaders' two sisters: they all share roughly the same amount of genes, but she would swear that her younger sister had completely different parents because she had different developmental outcomes (but over time, she looks more like her older sisters in terms of values and behavior) -- Scarr 1992 identified four factors: genetic differences (even identical twins have these because of pre-birth mutations or copying errors in their originally identical genomes; siblings differ in 50% of the genes on which people differ), differences in treatment by parents and others (parents tend to provide more sensitive care to easygoing infants than to difficult ones; by year 2, parents of difficult children are often angry with them even when the children have done nothing wrong in the immediate situation. teachers tend to provide positive attention and encouragement to students who are learning well and well behaved but tend to be openly critical and deny students' requests for special help with students who are doing poorly and are disruptive), differences in reactions to similar experiences (children who think their parents favor the other sibling, 69% of negative events that affect the whole family elicited fundamentally different reactions from siblings), and different choices of environments (choose activities and friends, accept or choose niches for themselves like "the smart one" and strive to live up to the label) -- a study of 11- to 17-year-olds found that the grades of children who were highly engaged with school changed in more positive directions than would have been predicted by their genetic background or family environments alone. also, children of high intelligence were less negatively affected by adverse family environments than were other children.