Chapter 9
Puberty and Oversleeping
Have you ever wondered why teenagers seem to sleep so much? Researchers have found that puberty is triggered by changes in the brain, including the release of certain hormones, which occur only during periods of deep sleep(D'Ambrosio & Redline, 2014; Shaw et al., 2012). This finding suggests that getting adequate, deep (slow-wave) sleep (see Chapter 5) during adolescence is an essential part of activating the reproductive system. Can you see why the increasing number of sleep problems in adolescents is a cause for concern, and why parents should actually be encouraging "oversleeping" in their teenagers?
critical periods
In addition, naturists believe there are ________or windows of opportunity, that occur early in life when exposure to certain stimuli or experiences is necessary for proper development.
BEHAVIOR 1. Sexual 2. Touching 3. Friendship 4. Personality 5. Cognitive abilities
MORE OFTEN SHOWN BY MEN 1.Begin masturbating sooner in life cycle and higher overall occurrence rates Start sexual life earlier and have first orgasm through masturbation More likely to recognize their own sexual arousal More orgasm consistency with sexual partner 2.Touched, kissed, and cuddled less by parents Less physical contact with other men and respond more negatively to being touched More likely to initiate both casual and intimate touch with sexual partner 3.Larger number of friends and express friendship by shared activities 4. More aggressive from a very early age More self-confident of future success Attribute success to internal factors and failures to external factors Achievement more task oriented; motives are mastery and competition More self-validating Higher self-esteem 5. Slightly superior in math and visuospatial skills
behavioral genetics
One of the major goals of the new field of _______, which studies the interplay of heredity and the environment, is to identify and study these polygenic traits.
Brain Development
Our brains and other parts of the nervous system grow faster than any other part of the body during both prenatal development and the first two years of life, as illustrated in Figure 9.8. This brain development and learning occur primarily because neurons grow in size. Also, the number of dendrites, as well as the extent of their connections, increases
Sex and Gender Differences
Physical anatomy is the most obvious biological sex difference between men and women. In addition to biological sex differences, scientists have noted numerous gender differences that affect our cognitive and personality development (Table 9.4). Keep in mind that these variations are statistically small, however, and represent few meaningful differences.
Harlow's study and contact comfort Although Harlow's studies of attachment in infant monkeys would be considered unethical today, it did clearly demonstrate that touch, and not feeding, is crucial to attachment.
Thanks in part to Harlow's research, psychologists discovered that contact comfort, the pleasurable, tactile sensations provided by a soft and cuddly "parent," is one of the most important variables in attachment (Figure 9.19). Further support comes from a study described in Chapter 4, which explains why hospitals now encourage premature babies to receive "kangaroo care," in which babies have skin-to-skin contact with a parent. For more information on how touch affects us—even as adults—see the following
wear-and-tear theory.
The second major explanation of primary aging is _______Like any machine, repeated use and abuse of our organs and cell tissues cause our human bodies to simply wear out over time.
sensorimotor stage
The sensorimotor stage lasts from birth until "significant" language acquisition (about age 2). During this time, children explore the world and develop their schemas primarily through their senses and motor activities—hence the term sensorimotor.
In the adolescent male, the testes, scrotum, and penis develop, and he experiences his first ejaculation (spermarche).
The testes and ovaries produce hormones that lead to the development of secondary sex characteristics, such as the growth of pubic hair, deepening of the voice and growth of facial hair in men, and growth of breasts in women (Figure 9.12). Do you recall how changes in height and weight, breast development and menstruation for girls, and a deepening voice and beard growth for boys were such important milestones for you and your adolescent peers?
Adulthood
When does adulthood begin? In Western cultures, many define it as beginning after high school or college graduation, whereas others mark it as when we get our first stable job and become self-sufficient. Adulthood is typically divided into at least three periods: emerging/young adulthood (ages 20-45), middle adulthood (ages 45-60), and late adulthood (ages 60 to death).
Morality—Personal Trait or the Situation?
Which do you believe is the better predictor of moral behavior—the person or the situation? You've undoubtedly seen this dilemma when students are faced with a choice to cheat on an exam or shoplift. How about the case of Lance Armstrong, who chose to use performance-enhancing drugs in sports competition? Was it the situation or his personal morality that most influenced his behavior?
accommodation
existing ideas are modified to fit new information. Accommodation generally occurs when new information or stimuli cannot be assimilated. New schemas are developed or old schemas are changed to better fit with the new information. An infant's first attempt to eat solid food with a spoon is a good example of accommodation
Sex and Gender Influences on Development Imagine for a moment what your life would be like if you were a member of the other sex. Would you think differently? Would you be more or less sociable and outgoing? Would your career plans or friendship patterns change? In this section, we will explore how our development is affected by sex (a biological characteristic determined at the moment of conception)
gender (psychological and sociocultural meanings added to biological maleness or femaleness)
Assimilation
is the process of absorbing new information into existing schemas. For instance, infants use their sucking schema not only in sucking nipples, but also in sucking blankets and fingers
Maturation and hormone secretion cause rapid development of the ovaries, uterus, and vagina, and the onset of menstruation (menarche) in the adolescent female
puberty in females
menarche
the first menstrual period
Touch
Harry Harlow and his colleagues (1950, 1971) also investigated the variables that might affect attachment. They created two types of wire-framed surrogate (substitute) "mother" monkeys: one covered by soft terry cloth and one left uncovered (Figure 9.18). The infant monkeys were fed by either the cloth or the wire mother, but they otherwise had access to both mothers. The researchers found that regardless of which surrogate was feeding them, the infant monkeys overwhelmingly preferred the soft, cloth surrogate-even when the wire surrogate was the one providing the food. In addition, monkeys "reared" by a cloth mother clung frequently to the soft material of their surrogate mother and developed greater emotional security and curiosity than did monkeys assigned to the wire mother.
Vygotsky's zone of proximal development (ZPD)
Have you heard of "instructional scaffolding"? This term refers to providing support during the learning process that is tailored to the needs of the student. Vygotsky was one of the first to apply the general idea of scaffolding to early cognitive development. He proposed that the most effective teaching focuses on tasks between those a learner can do without help (the lower limit) and those he or she cannot do even with help (the upper limit). In this middle, zone of proximal development (ZPD), tasks and skills can be "stretched" to higher levels with the guidance and encouragement of a more knowledgeable person.
Stages of Cognitive Development
According to Piaget, all children go through approximately the same four stages of cognitive development, regardless of the culture in which they live (Process Diagram 9.2). Piaget also believed that these stages cannot be skipped because skills acquired at earlier stages are essential to mastery at later stages
Why do we go through so many physical changes? What causes us to age and die? Setting aside aging and deaths resulting from disease, abuse, or neglect, known as secondary aging, let's focus on primary aging (gradual, inevitable age-related changes in physical and mental processes).
According to cellular-clock theory, primary aging is genetically controlled. Once the ovum is fertilized, the program for aging and death is set and begins to run. Researcher Leonard Hayflick (1965, 1996) found that human cells seem to have a built-in life span. After about 100 doublings of laboratory-cultured cells, they cease to divide. Based on this limited number of cell divisions, Hayflick suggests that we humans have a maximum life span of about 120 years—we reach the Hayflick limit. Why? One answer may be that small structures on the tips of our chromosomes, called telomeres, shorten each time a cell divides. After about 100 replications, the telomeres are too short and the cells can no longer divide
Ready for responsibility?
Adolescence is not a universal concept. Unlike the United States and other Western nations, some non-industrialized countries have no need for a slow transition from childhood to adulthood; children simply assume adult responsibilities as soon as possible.
Adolescence
Adolescence is the loosely defined transition period of development between childhood and adulthood. In the United States, it roughly corresponds to the teenage years. However, the concept of adolescence and its meaning vary greatly across cultures
puberty
Adolescence officially begins with______, the period of time when we mature sexually and become capable of reproduction. And one of the clearest and most dramatic physical signs of puberty is the growth spurt, which is characterized by rapid increases in height, weight, and skeletal growth and by significant changes in reproductive structures and sexual characteristic
Personality Development temperament
As an infant, did you lie quietly and seem oblivious to loud noises? Or did you tend to kick and scream and respond immediately to every sound? Did you respond warmly to people, or did you fuss, fret, and withdraw? Your answers to these questions help determine what developmental psychologists call your__________, an individual's innate disposition, behavioral style, and characteristic emotional response.
Vygotsky Versus Piaget
As influential as Piaget's account of cognitive development has been, there are other important theories, and criticisms of Piaget, to consider. For example, Russian psychologist Lev Vygotsky emphasized the sociocultural influences on a child's cognitive development, rather than Piaget's internal schemas (Vygotsky, 1962). According to Vygotsky, children construct knowledge through their culture, language, and collaborative social interactions with more experienced thinkers. Unlike Piaget, Vygotsky believed that adults play an important instructor role in development and that this instruction is particularly helpful when it falls within a child's zone of proximal development
Reliving Your Own Adolescent Egocentrism
Do these descriptions of the imaginary audience and personal fable ring true for you? If so, do you now understand how these beliefs might help explain some of the problems and challenges you faced in adolescence? As implied in this photo, many teens have difficulty accepting comfort and support from parents due to their belief that no one has ever felt or experienced what they have. One young woman remembered being very upset in middle school when her mother tried to comfort her over the loss of an important relationship. "I felt like she couldn't possibly know how it felt—no one could. I couldn't believe that anyone had ever suffered like this or that things would ever get better." Best advice for parents? Have patience and be comforting and reassuring. Teenagers whose parents use harsh verbal discipline (yelling or making serious threats) show more symptoms of depression and more behavior problems (lying, trouble in school, fighting with peers)
Achievement in Later Years
Our cognitive abilities generally grow and improve throughout our life span, as demonstrated by the achievements of people like Justices Ruth Bader Ginsburg and Antonin Scalia of the U.S. Supreme Court. Justice Scalia served from 1986 until his death in 2016, just shy of his 80th birthday. For decades Justice Scalia was the leading conservative voice on the Court. In her younger years, Justice Ginsburg worked tirelessly as a staunch courtroom advocate. Now in her 80s, she serves as a leading liberal voice on the Supreme Court. Fun Fact: Despite their diametrically opposed political and legal philosophies, Justice Scalia and Justice Ginsburg had a great deal of mutual respect for one another and were known to be very close friends.
PARENTING STYLE Authoritarian(high C, low W) DESCRIPTION Parents are rigid and punitive (high C), but low on warmth and responsiveness (low W). EXAMPLE "I don't care what you want. Just do it my way, or else! EFFECT ON CHILDREN Children tend to be easily upset, moody, aggressive, and often fail to learn good communication skills.
PARENTING STYLE Authoritative(high C, high W) DESCRIPTION Parents generally set and enforce firm limits (high C), while being highly involved, tender, and emotionally supportive high W). EXAMPLE "I really care about you, but there are rules, and you need to be responsible." EFFECT ON CHILDREN Children become self-reliant, self-controlled, high achieving, and emotionally well adjusted; also seem more content, goal oriented, friendly, and socially competent.
Life Span Development
STAGE APPROXIMATE AGE Prenatal Conception to birth Infancy Birth to 18 months Early childhood 18 months to 6 years Middle childhood 6 to 12 years Adolescence 12 to 20 years Young adulthood 20 to 45 years Middle adulthood 45 to 60 years Late adulthood 60 years to death
Changes in physical development over the life span
As this series of photos of your two textbook authors show, physical changes occur throughout our lives. Our cognitive, social, and emotional processes, as well as our personalities also are continually changing, but the changes aren't as visible. (
Gender Roles and Teenagers
How do gender roles affect older children? Researchers in one study asked teenagers (ages 13 to 16) to describe two positive and two negative stories about themselves (Fivush et al., 2012). When the researchers examined the stories, they found striking differences. The stories told by girls were generally longer, more coherent, more detailed, and more descriptive of their own feelings and emotions. The boys' stories, in contrast, were more matter-of-fact and less self-reflective. What causes such differences? One factor may be that parents talk to boys and girls about emotions in different ways.
Early Childhood Development
Like the prenatal period, early childhood is a similar time of rapid physical development. Let's explore three key areas of change in early childhood: brain, motor, and sensory/perceptual development.
1.Inability to perform mental operations
Piaget labeled this period "preoperational" because the child lacks operations, meaning the ability to imagine an action and mentally reverse it. For instance, a preoperational child would not understand that milk poured into a tall, thin glass is not "more" than the same amount poured into short, wide glass This is because they lack reversibility, and the concept of conservation—the principle that certain characteristics (such as volume) stay the same, even though appearances may change
Adolescent egocentrism or narcissism?
Piaget describes most children and adolescents as being egocentric, and egocentrism is a major characteristic of narcissism. Given the growing popularity of taking and posting self-portraits ("selfies") on social media, have you wondered if this practice might increase narcissism? Research on this topic does find that narcissistic individuals do in fact take and post more "selfies," and that these actions have a self-reinforcing effect that maintains the narcissist's positive self-views Along with the benefits of this cognitive style come several problems. Adolescents in the early stages of the formal operational period demonstrate a type of egocentrism different from that of the preoperational child (see the photo on the left and the following Psychology and You feature). Adolescents certainly recognize that others have unique thoughts and perspectives. However, they may fail to differentiate between what they are thinking and what others are thinking. For example, if they get a new haircut or fail to make the sports team, they may be overly concerned about how others will react. Instead of considering that everyone is equally wrapped up in his or her own appearance, concerns, and plans, they tend to believe that they are the center of others' thoughts and attentions. David Elkind (1967, 2007) referred to this as the imaginary audience. While believing that others are always watching and evaluating them (the imaginary audience), adolescents also, ironically, tend to believe they are special and unique. They alone are having insights or difficulties that no one else understands or experiences. Sadly, these feelings of special uniqueness, known as the personal fable, are associated with several forms of risk taking, such as engaging in sexual intercourse without protection, driving dangerously, indoor tanning, and experimenting with drugs (Banerjee et al., 2015; Landicho et al., 2014). Adolescents apparently recognize the dangers of risky activities, but they believe the rules and statistics just don't apply to them. Recall from the discussion earlier that psychologists now believe these effects may be largely due to the teen's less-than-fully-developed frontal lobes In sum, the imaginary audience apparently results from an inability to differentiate the self from others, whereas the personal fable may be a product of differentiating too much. Thankfully, these two forms of adolescent egocentrism tend to decrease during later stages of the formal operational period.
Formal Operational Stage
The final period in Piaget's theory, the ___________ typically begins around age 11. In this stage, children begin to apply their operations to abstract concepts in addition to concrete objects. They become capable of hypothetical thinking ("What if?"), which allows systematic formulation and testing of concepts. For example, before filling out applications for part-time jobs, adolescents may think about possible conflicts with school and friends, the number of hours they want to work, and the kind of work for which they are qualified. Formal operational thinking also allows the adolescent to construct a well-reasoned argument based on hypothetical concepts and logical processes. Consider the following argument: 1.If you hit a glass with a feather, the glass will break. 2.You hit the glass with a feather. What is the logical conclusion? The correct answer, "The glass will break," is contrary to fact and direct experience. Therefore, the child in the concrete operational stage would have difficulty with this task, whereas the formal operational thinker understands that this problem is about abstractions that need not correspond to the real world.
Preoperational Stage
(roughly ages 2 to 7), language advances significantly, and the child begins to think symbolically—using symbols, such as words, to represent concepts. Three other qualities characterize this stage: inability to perform mental operations, egocentrism, and animism.
gender roles
(societal expectations for "appropriate" male and female thoughts, feelings, and actions), and cultural differences.
Theoretical Issues Almost every area of research in human development frames questions around three major issues:
1. Nature or nurture? How do both genetics (nature) and life experiences (nurture) influence development? According to the nature position, development is largely governed by automatic, genetically predetermined signals in a process known as maturation. Just as a flower unfolds in accord with its genetic blueprint, humans crawl before we walk, and walk before we run.
Social-learning theorists emphasize the power of the immediate situation and observable behaviors on gender-role development. Girls learn how to be "feminine," and boys learn how to be "masculine" in two major ways: (1) They receive rewards or punishments for specific gender-role behaviors, and (2) they watch and imitate the behavior of others, particularly their same-sex parent (Bandura, 1989, 2008; Risman & Davis, 2013). A boy who puts on his father's tie or baseball cap wins big, indulgent smiles from his parents. But what would happen if he put on his mother's nightgown or lipstick? Parents, teachers, and friends generally reward or punish behaviors according to traditional gender-role expectations. Thus, a child "socially learns" what it means to be male or female.
According to the cognitive-developmental theory, social learning is part of gender-role development, but it's much more than a passive process of receiving rewards or punishments and modeling others. Instead, cognitive developmentalists argue that children actively observe, interpret, and judge the world around them (Bem, 1981, 1993; Leaper, 2013; Starr & Zurbriggen, 2016). As children process information about the world, they also create internal rules governing correct behaviors for boys and for girls. On the basis of these rules, they form gender schemas (mental images) of how they should act.
Late Adulthood
After middle age, most physical changes in development are gradual and occur in the heart and arteries, and in the sensory receptors. Cardiac output (the volume of blood pumped by the heart each minute) decreases, whereas blood pressure increases, due to the thickening and stiffening of arterial walls. Visual acuity and depth perception decline, hearing acuity lessens (especially for high-frequency sounds), smell sensitivity decreases, and some decline in cognitive and memory skills occurs
Ainsworth's Levels of Attachment
Although physical contact between caregiver and child appears to be an innate, biological part of attachment, Mary Ainsworth and her colleagues (1967, 1978) discovered several interesting differences in the type and level of human attachment (Figure 9.20). For example, infants with a secure attachment style generally had caregivers who were sensitive and responsive to their signals of distress, happiness, and fatigue. In contrast, anxious/avoidant infants had caregivers who were aloof and distant, and anxious/ambivalent infants had inconsistent caregivers, who alternated between strong affection and indifference. Caregivers of disorganized/disoriented infants tended to be abusive or neglectful Research on infant attachment For most children, parents are the earliest and most important factor in social development, and the attachment between parent and child is of particular interest to developmental psychologists.
Emerging/Young Adulthood
Although young adulthood is generally considered to begin at age 20, many developmental psychologists have added a new term, _____, to refer to the time from the end of adolescence to the young-adult stage, approximately ages 18-25. This stage, which is found primarily in modern cultures, is characterized by the search for a stable job, self-sufficiency, and/or marriage and parenthood, along with five distinguishing features
Attachment
An infant arrives in the world with a multitude of behaviors that encourage a strong bond of____________with primary caregivers. Returning to our earlier discussion of the nature-nurture controversy, researchers who advocate the nativist, or innate, position suggest that newborn infants are biologically equipped with verbal and nonverbal behaviors (such as crying, clinging, and smiling) and imprinting ("following") behaviors (such as crawling and walking after the caregiver) that elicit instinctive nurturing responses from the caregiver (Bowlby, 1969, 1989, 2000). Studies have found numerous benefits to a child's good attachment, including lower levels of aggressive behavior, fewer sleep problems, and less social withdrawal (Ding et al., 2014). But as was the sad case of Genie, discussed at the start of this chapter, some children never form appropriate, loving attachments. What happens to these children? Researchers have investigated this question in two ways: They have looked at children and adults who spent their early years in institutions without the stimulation and love of a regular caregiver, as well as those who lived at home but were physically isolated under abusive conditions. Tragically, infants raised in impersonal or abusive surroundings suffer from a number of problems. They seldom cry, coo, or babble; they become rigid when picked up; and they have few language skills. As for their social-emotional development, they tend to form shallow or anxious relationships. Some appear forlorn, withdrawn, and uninterested in their caretakers, whereas others seem insatiable in their need for affection. They also tend to show intellectual, physical, and perceptual deficiencies, along with increased susceptibility to infection, and neurotic "rocking" and isolation behaviors. There are even cases where healthy babies who were well-fed and kept in clean diapers—but seldom held or stimulated—actually died from lack of attachment (Bowlby, 2000; Duniec & Raz, 2011; Spitz & Wolf, 1946). Some research suggests that childhood emotional abuse and neglect is as harmful, in terms of long-term mental problems, as physical and sexual abuse (Spinazzola et al., 2014).
epigenetics
Another new and related field of research, known as ______, studies how non-genetic factors can dramatically affect how (and if) inherited genes are expressed throughout our lives (Brody et al., 2016; Iakoubov et al., 2015; Wallack & Thornburg, 2016). Unlike simple genetic transmission, which is based on changes in the DNA sequence, changes in gene expression can have other causes, such as age, environment, lifestyle, or disease. (The term "epi" means "above" or "outside of.") In other words, nurture can shape nature! Epigenetic factors can switch genes "ON" or "OFF." For example, epigenetic factors like malnutrition or childhood abuse can prevent a child from reaching his or her full potential genetic height or maximum genetic intelligence (Denholm et al., 2013; Venable & Raine, 2016). The good news is that with environmental changes even identical twins are not destined to develop the same diseases.
1.Moral reasoning versus behavior
Are people who achieve higher stages on Kohlberg's scale really more moral than others? Or do they just "talk a good game"? Some researchers have shown that a person's sense of moral identity, meaning the use of moral principles to define oneself, is often a good predictor of his or her behavior in real-world situations (Johnston et al., 2013; Stets & Carter, 2012). But others have found that situational factors are better predictors of moral behavior (Bandura, 1989, 2008; Frimer et al., 2014; Noval & Stahl, 2015). For example, research participants are more likely to steal when they are told the money comes from a large company rather than from individuals (Greenberg, 2002). And both men and women tell more sexual lies during casual relationships than during close relationships (Williams, 2001).
Want to be Happier? Grow Older!
As just discussed here and in Chapters 1 and 7, researchers have found an increase in happiness and overall well-being as we grow older (Kern et al., 2014; Riediger & Luong, 2016; Sutin et al., 2013). Why? One interesting possibility comes from research showing that older adults tend to prefer and pay more sustained attention to positive over negative information (Carstensen, 1993, 2006; Livingstone & Isaacowitz, 2016; Reed et al., 2014). Further research finds that this age-related positivity effect may even increase immune functioning, overall healthy aging, and life satisfaction (Kalokerinos et al., 2014; Mikels & Shuster, 2016). Interestingly, younger people tend to shown an opposite approach—preferring negative over positive information and events. Can you see how this might help explain why the college years can feel so painful and troublesome in your 20s, while in later years they might be remembered as "the best years of your life?" It appears that older adults have developed greater emotional regulation, and that they deliberately focus their attention and memory in a positive direction. How can we use this information to improve our life regardless of age? In addition to deliberately focusing on positive information, research shows that practicing gratitude exercises can increase our well-being, happiness, and life satisfaction (Chaves et al., 2016; Israel-Cohen et al., 2015; Watkins et al., 2015). Simple examples of these exercises include creating a list of things we're grateful for, keeping a daily gratitude list of the top three things that we're grateful for, and writing letters to and/or visiting people who have had a positive impact on our lives.
Adults Need Hugs Too!
As we've just seen, contact comfort is critical for the physical and mental well-being of both monkeys and human infants. But did you know that the touch of others is an invaluable and important asset throughout our life span? Human touch has been repeatedly shown to be an effective way to solicit and provide social support (e.g., Robinson et al., 2015). It also can reduce the perception of pain, heart rate and blood pressure, and increase levels of oxytocin. Sadly, elderly nursing home residents and others often feel unwanted and their unsatisfied desire for social touch can lead to "touch hunger" (Ben-Zeév, 2014; Gallace & Spence, 2010; Rydé & Hjelm, 2016; Uvnäs-Moberg et al., 2015). Even something as simple as a hand massage can reduce disruptive behaviors in patients with dementia (Fu et al., 2013). Hugs appear to be a particularly effective way of touching. In fact, people who get more frequent hugs are even less susceptible to infection and experience less severe illness symptoms (Cohen et al., 2015). In this study involving 404 healthy adults, perceived support was first assessed by a questionnaire, and frequencies of interpersonal conflicts and receiving hugs were derived from telephone interviews conducted on 14 consecutive evenings. Then, the participants were intentionally exposed to a common cold virus and monitored in quarantine to assess infection and signs of illness. The results showed that perceived social support reduced the risk of infection associated with experiencing conflicts. Hugs were responsible for one-third of the protective effect of social support. Among infected participants, greater perceived social support and more frequent hugs both resulted in less severe illness symptoms whether or not they experienced conflicts. Why? The researchers in this study suggest that a hug by a trusted person may act as an effective means of conveying support and that increasing the frequency of hugs might be an effective means of reducing the deleterious effects of stress.
Hazards to Prenatal Development
As you recall, human development begins with the genes we inherit from our biological parents, and epigenetic factors, like age, lifestyle, and diseases, can dramatically affect how (and if) these inherited genes are expressed. For example, during pregnancy the placenta connects the fetus to the mother's uterus and serves as the link for delivery of food and excretion of wastes. Moreover, it screens out some, but not all, harmful substances. As you can see in Table 9.2, environmental hazards such as X-rays and toxic waste, drugs, and diseases can still cross the placental barrier and have an epigenetic effect—meaning they leave a chemical mark on the DNA that abnormally switches the fetus's genes on or off. These influences generally have the most devastating effects during the first three months of pregnancy, making this a critical period in development.
The Teenage Brain
As you recall, our brains and other parts of the nervous system grow faster than any other part of our bodies during both prenatal development and the first 2 years of life. In contrast to the rapid synaptic growth experienced in the earlier years, the adolescent's brain actively destroys (prunes) unneeded connections. Although it may seem counterintuitive, this pruning actually improves brain functioning by making the remaining connections between neurons more efficient. Interestingly, full maturity of the frontal lobes is not accomplished until the mid-twenties (Figure 9.13). Do you recall your teenage years as a time of exaggerated self-consciousness, feelings of special uniqueness, and risky behaviors? Psychologists now believe these effects may be largely due to your less-than-fully-developed frontal lobes
Concrete Operational Stage
At approximately age 7, children enter the _______. During this time, many important thinking skills emerge. However, as the name implies, thinking tends to be limited to concrete, tangible objects and events. Unlike preoperational children, youngsters in this stage are less egocentric in their thinking and become capable of true logical thought. As most parents know, children now stop believing in Santa Claus because they logically conclude that one man can't deliver presents to everyone in one night.
Sensory and Perceptual Development
At birth, and during the final trimester of pregnancy, the developing child's senses are quite advanced For example, research shows that a newborn infant prefers his or her mother's voice, providing evidence that the developing fetus can hear sounds outside the mother's body This raises the interesting possibility of fetal learning, and some have advocated special stimulation for the fetus as a way of increasing intelligence, creativity, and general alertness In addition, a newborn can smell most odors and distinguish between sweet, salty, and bitter tastes. Breast-fed newborns also recognize the odor of their mother's milk compared to other mother's milk, formula, and other substances Similarly, the newborn's sense of touch and pain is highly developed, as evidenced by reactions to circumcision and to heel pricks for blood testing, and by the fact that their pain reactions are lessened by the smell of their own mother's milk The newborn's sense of vision, however, is poorly developed. At birth, an infant is estimated to have vision between 20/200 and 20/600 (Haith & Benson, 1998). Imagine what the infant's visual life is like: The level of detail you see at 200 or 600 feet (if you have 20/20 vision) is what an infant sees at 20 feet. Within the first few months, vision quickly improves, and by 6 months it is 20/100 or better. At 2 years, visual acuity is nearly at the adult level of 20/20
Prenatal Development
At the moment of your conception, your biological mother and father each contributed 23 chromosomes, which are threadlike, linear strands of DNA(deoxyribonucleic acid) encoded with their genes (Figure 9.6). Interestingly, DNA of all humans (except identical twins) has unique, distinguishing features, much like the details on our fingerprints. This uniqueness is commonly used in forensics to exclude or identify criminal suspects. In addition, DNA analysis is often used for genetic testing during prenatal development to identify existing or potential future disorders.
Gender-Role Development
By age 2, children are well aware of gender roles. From parents and other social forces, they quickly learn that boys "should" be strong, independent, aggressive, dominant, and achieving, whereas girls "should" be soft, dependent, passive, emotional, and "naturally" interested in children. Unfortunately, such expectations and stereotypes for how women and men should think, feel, or act may seriously limit both sexes in their choice of friendships, activities, and career goals (Best & Bush, 2016; Gianettoni & Guilley, 2016; Latu & Schmid Mast, 2016). The existence of similar gender roles in many cultures suggests that evolution and biology may play a role in their formation. However, most research emphasizes two major psychosocial theories of gender-role development: social learning and cognitive developmenta
2.Egocentrism
Children at this stage are egocentric, which refers to the preoperational child's limited ability to distinguish between his or her own perspective and someone else's. Egocentrism is not the same as "selfishness." Preschoolers who move in front of you to get a better view of the TV, or repeatedly ask questions while you are talking on the telephone, are not being selfish. They are demonstrating their natural limits and egocentric thought processes. Children in this stage naively assume that others see, hear, feel, and think exactly as they do. Consider the following telephone conversation between a 3-year-old, who is at home, and her mother, who is at work: MOTHER: Emma, is that you? EMMA: (Nods silently.) MOTHER: Emma, is Daddy there? May I speak to him? EMMA: (Twice nods silently.) Egocentric preoperational children fail to understand that the phone caller cannot see their nodding head. Charming as this is, preoperational children's egocentrism also sometimes leads them to believe their "bad thoughts" caused their sibling or parent to get sick or that their misbehavior caused their parents' marital problems. Because they think the world centers on them, they often cannot separate reality from what goes on inside their own head.
Secondary sex characteristics
Complex physical changes in puberty primarily result from hormones secreted from the ovaries and testes, the pituitary gland in the brain, and the adrenal glands near the kidneys.
3.Animism
During this stage, children generally believe objects, such as the moon, trees, clouds, and bars of soap, have motives, feelings, and intentions (for example, "the moon follows me when I walk," "dark clouds are angry" and "soap sinks to the bottom of the bathtub because it is tired"). Animism refers to the belief that all things are living (or animated).
1.Identity exploration —young people decide who they are and what they want out of life. 2.Instability —a time marked by multiple changes in residence and relationships. 3.Self-focus —freed from social obligations and commitments to others, young people at this stage are focused on what they want and need before constraints of marriage, children, and career. 4.Feeling in-between —although taking responsibility for themselves, they still feel in the middle between adolescence and adulthood. 5.Age of possibilities —a time of optimism and belief that their lives will be better than their parents.
During this time period, some individuals experience modest physical increases in height and muscular development, and most of us find this to be a time of maximum strength, sharp senses, and overall stamina. However, a decline in strength and speed becomes noticeable in the 30s, and our hearing starts to decline as early as our late teens.
As you can see in Figure 9.7, heavy maternal drinking may lead to a cluster of serious abnormalities called fetal alcohol spectrum disorders (FASD). The most severe form of this disorder is known as fetal alcohol syndrome (FAS). Recent research suggests that alcohol may leave chemical marks on DNA that abnormally turn off or on specific genes (Mason & Zhou, 2015). Tobacco might have a similar epigenetic effect. For example, children whose mothers smoked during pregnancy are more likely to be obese as adolescents, perhaps because in-utero exposure to nicotine changes a part of the brain that increases a preference for fatty foods (Haghighi et al., 2013, 2014).
Fetal alcohol spectrum disorders (FASD) Prenatal exposure to alcohol can result in FASD, and it's most severe form is called fetal alcohol syndrome (FAS), including facial abnormalities and stunted growth. But the most disabling features of FAS are brain damage and neurobehavioral problems, ranging from hyperactivity and learning disabilities to intellectual disability, depression, and psychoses (
imprinting
For example, many newborn animals, and theoretically humans, form rigid attachments to particular stimuli shortly after birth, a process called
Attachment Styles in Adulthood
In addition to finding varying levels of infant attachment to parents, researchers have examined adult attachment patterns independent of their earlier infant patterns, with several interesting and/or troublesome results. For example, a secure attachment pattern is associated with higher subjective well-being (SWB), whereas adolescents and young adults with avoidant and anxious attachment patterns show more depressive symptoms. Another study found an association between pathological jealousy and the anxious/ambivalent style of attachment Researchers also looked at how varying types of attachment as infants might shape our later adult styles of romantic love. If we developed a secure, anxious/ambivalent, anxious/avoidant, or disorganized/disoriented style as infants, we tend to follow these same patterns in our adult approach to intimacy and affection. For example, young adults who experienced either unresponsive or overintrusive parenting during childhood are more likely to avoid committed romantic relationships as adults (Dekel & Farber, 2012). You can check your own romantic attachment style in the following Psychology and You feature. However, keep in mind that it's always risky to infer causation from correlation (see Chapter 1). Even if early attachment experiences are correlated with our later relationships, they do not determine them. Throughout life, we can learn new social skills and different approaches to all our relationships.
For women between ages 45-55, menopause, the cessation of the menstrual cycle, is the second most important life milestone in physical development. The decreased production of estrogen (the dominant female hormone) produces certain physical changes, including decreases in some types of cognitive and memory skills. However,the popular belief that menopause (or "the change of life") causes serious psychological mood swings is not supported by current research. In fact, younger women are more likely to report irritability and mood swings, whereas women at midlife generally report positive reactions to aging, and the end of the menstrual cycle. They're also less likely to have negative experiences such as headaches
In contrast to women, men experience a more gradual decline in hormone levels, and most men can father children until their 70s or 80s. to feel depressed and to question their life progress. ThPhysical changes such as unexpected weight gain, decline in sexual responsiveness, loss of muscle strength, and graying or loss of hair may lead some men (and women as well)ey often see these alterations as a biological signal of aging and mortality. Such physical and psychological changes in men are generally referred to as the male climacteric (or andropause). However, the popular belief that almost all men (and some women) go through a deeply disruptive midlife crisis, experiencing serious dissatisfaction with their work and personal relationships, is largely a myth.
longitudinal design
In contrast, a______ takes repeated measures of one person or a group of same-aged people over a long period of time to see how the individual or the group changes over time. For example, a group of developmental researchers wondered if peer ratings of personality taken during childhood might be better predictors of later adult personality than self-ratings (Martin-Storey et al., 2012). They first asked grade school children in 1976-1978 to rate themselves and their peers on several personality factors, such as likeability, aggression, and social withdrawal. In 1999-2003, the researchers returned and asked the same participants, now in mid-adulthood, to complete a second series of personality tests. As hypothesized, the peer ratings were better than self-ratings in predicting adult personality. Does this finding surprise you? If so, try contacting some of your childhood peers and then compare notes on how you remember one another's personality as children and now as adults.
developmental psychology
Just as some parents carefully document their child's progress throughout his or her life, the field of __________ studies growth and change throughout the eight major stages of life—from conception to death, or "womb to tomb" (Table 9.1). These studies have led to three key theoretical issues.
Moral Development In Europe, a cancer-ridden woman was near death, but an expensive drug existed that might save her. The woman's husband, Heinz, begged the druggist to sell the drug cheaper or to let him pay later. But he refused. Heinz became desperate and broke into the druggist's store and stole it. (Adapted from Kohlberg, 1964, pp. 18-19) Was Heinz right to steal the drug? What do you consider moral behavior? Is morality "in the eye of the beholder," or are there universal moral truths and principles? Whatever your answer, your ability to think, reason, and respond to Heinz's dilemma may demonstrate your current level of moral development. One of the most influential researchers in moral development was Lawrence Kohlberg (1927-1987). He presented what he called "moral stories" like the Heinz dilemma to people of all ages, not to see whether they judged Heinz right or wrong but to examine the reasons they gave for their decisions. On the basis of his findings, Kohlberg (1964, 1984) developed a model of moral development, with three broad levels each composed of two distinct stages (Process Diagram 9.3). Individuals at each stage and level may or may not support Heinz's stealing of the drug, but their reasoning changes from level to level. At the first, precoventional level, morality is self-centered and based on rewards, punishments, and exchange of favors. In contrast, during the second, conventional level, moral judgments are based on compliance with the rules and values of society. And, at the third, postconventional level, individuals develop personal standards for right and wrong. They define morality in terms of abstract principles and values that apply to all situations and societies.
Kohlberg's Stages of Moral Development
Erikson's Psychosocial Theory
Like Piaget and Kohlberg, Erik Erikson developed a stage theory of development. He identified eight psychosocial stages of social development, with each stage marked by a "psychosocial" crisis or conflict that must be successfully resolved for proper future development
Piaget's Four Stages of Cognitive Development
Limits Lacks "significant" language and object permanence (understanding that things continue to exist even when not seen, heard, or felt) Abilities Uses senses and motor skills to explore and develop cognitively Example Children at this stage like to explore and play with their food.
BEHAVIOR 1. Sexual 2. Touching 3. Friendship 4. Personality 5. Cognitive abilities
MORE OFTEN SHOWN BY WOMEN 1. Begin masturbating later in life cycle and lower overall occurrence rates Start sexual life later and have first orgasm from partner stimulation Less likely to recognize their own sexual arousal Less orgasm consistency with sexual partner 2. Touched, kissed, and cuddled more by parents More physical contact with other women and respond more positively to being touched Less likely to initiate either casual or intimate touch with sexual partner 3. Smaller number of friends and express friendship by shared communication about self 4. Less aggressive from a very early age Less self-confident of future success Attribute success to external factors and failures to internal factors Achievement more socially directed, with emphasis on self-improvement More dependent on others for validation Lower self-esteem 5. Slightly superior in verbal skills
Middle Adulthood
Many physical changes during young adulthood happen so slowly that most people don't notice them until they enter their late 30s or early 40s. For example, around the age of 40, we first experience difficulty in seeing things close up and after dark, a thinning and graying of our hair, wrinkling of our skin, and a gradual loss in height coupled with weight gain
The name for each psychosocial stage reflects the specific crisis encountered at that stage and two possible outcomes. The crisis or task of most young adults is intimacy versus isolation. This age group's developmental challenge is establishing deep, meaningful relations with others. Those who don't meet this challenge risk social isolation. Erikson believed that the more successfully we overcome each psychosocial crisis, the better chance we have to develop in a healthy manner (Erikson, 1950).
Many psychologists agree with Erikson's general idea that psychosocial crises, which are based on interpersonal and environmental interactions, do contribute to personality development (Marcia & Josselson, 2013; Svetina, 2014). However, Erikson also has his critics (Arnett, 2015; Spano et al., 2010). Some evidence now suggests that people may approach these valued life tasks at different ages, and potentially in different orders. Furthermore, identity development often continues through the late 20s, and is not simply a task approached by adolescents (Carlsson et al., 2015). In addition, Erikson's psychosocial stages are difficult to test scientifically, and the labels he used to describe the eight stages may not be entirely appropriate cross-culturally. For example, in individualistic cultures, autonomy is highly preferable to shame and doubt. But in collectivist cultures, the preferred resolution might be dependence or merging relations (Berry et al., 2011). Despite their limits, Erikson's stages have greatly contributed to the study of North American and European psychosocial development. Also, by suggesting that development continues past adolescence, Erikson's theory has encouraged ongoing research and theory development across the life span.
Motor Development Compared to the hidden, internal changes in brain development, the orderly emergence of active movement skills, known as motor development, is easily observed and measured. A newborn's first motor abilities are limited to reflexes, or involuntary responses to stimulation (Chapter 2). For example, the rooting reflex occurs when something touches a baby's cheek: The infant will automatically turn its head, open its mouth, and root for a nipple. In addition to simple reflexes, the infant soon begins to show voluntary control over the movement of various body parts (Figure 9.9). Thus, a helpless newborn, who cannot even lift her head, is soon transformed into an active toddler capable of crawling, walking, and climbing. In fact, babies are highly motivated to begin walking because they can move faster than when crawling, and they get better with practice (Adolph & Berger, 2012; Berger, 2015). Keep in mind that motor development is largely due to natural maturation, but, like brain development, it can be affected by environmental influences, such as disease and neglect.
Milestones in motor development The acquisition and progression of motor skills, from chin up to walking up steps, is generally the same for all children, but the environment and personal experiences also play a role. In short, each child will follow his or her own personal timetable
Conception and your hereditary code
Note that genes are the basic building blocks of our entire biological inheritance (Garrett, 2015; Scherman, 2014). Each of our human characteristics and behaviors is related to the presence or absence of particular genes that control the transmission of traits. In some traits, such as blood type, a single pair of genes (one from each parent) determines what characteristics we will possess. When two genes for a given trait conflict, the outcome depends on whether the gene is dominant or recessive. A dominant gene reveals its trait whenever the gene is present. In contrast, the gene for a recessive trait is normally expressed only if the other gene in the pair is also recessive.
Adolescent growth spurt
Note the gender differences in height gain during puberty. Most girls are about two years ahead of boys in their growth spurt and are therefore taller than most boys between the ages of 10 and 14.
Parenting Styles How much of our personality comes from the way our parents treat us as we're growing up? Researchers since the 1920s have studied the effects of different methods of childrearing on children's behavior, development, and mental health. For example, one interesting study found that teenagers whose parents used a controlling style—such as withholding love or creating feelings of guilt—later have more difficulty working out conflicts with friends and romantic partners (Oudekerk et al., 2015). Other studies by Diana Baumrind (1980, 2013) found that parenting styles could be reliably divided into four broad patterns—permissive-neglectful, permissive-indulgent, authoritarian, and authoritative—which can be differentiated by their degree of control/demandingness (C) and warmth/responsiveness
Note: The last two parenting styles (authoritarian and authoritative) are very similar. An easy way to remember is to notice the two Rs in authoRitaRian, and imagine a Rigid Ruler. Then note the last two Ts in authoriTaTive, and picture a Tender Teacher.
Three Stages of Prenatal Development
Now that we've discussed the general principles of how our genes and our environment interact to form us as unique individuals, let's go back to the moment of your conception. At that point in time, you were a single cell barely 1/175 of an inch in diameter—smaller than the period at the end of this sentence. This new cell, called a zygote, then began a process of rapid cell division that resulted in a multimillion-celled infant (you) some nine months later.
object permanence
One important concept that infants lack at the beginning of the sensorimotor stage is object permanence—an understanding that objects continue to exist even when they cannot be seen, heard, or touched Prior to about 8 months of age, Piaget believed that infants tend to lack object permanence, as shown by the child in the first two photos, who apparently believes the toy no longer exists once it is blocked from sight. In contrast, the older child in the third photo supposedly knows that the object still exists even if it is hidden—as shown by her attempt to seek out the toy under the sofa. Piaget would have said that this child is demonstrating that she has formed a mental representation (a schema) of the object and has acquired a recognition of object permanence. Note however that modern researchers believe that object permanence appears much earlier than 8 months. Infants may fail to look for hidden objects because they don't know how to look for them, not because they believe the objects no longer exist (Baillargeon & DeVos, 1991; Berger, 2015; Gerson & Woodward, 2014). In other words, Piaget may have mistook infants' motor incompetence for conceptual incompetence.
Thomas and Chess's Temperament Theory
One of the earliest and most influential theories regarding temperament came from the work of psychiatrists Alexander Thomas and Stella Chess Thomas and Chess found that approximately 65% of the babies they observed could be reliably separated into three categories: 1.Easy children These infants were happy most of the time, relaxed and agreeable, and adjusted easily to new situations (approximately 40%). 2.Difficult children Infants in this group were moody, easily frustrated, tense, and overreactive to most situations (approximately 10%). 3.Slow-to-warm-up children These infants showed mild responses, were somewhat shy and withdrawn, and needed time to adjust to new experiences or people (approximately 15%).
Follow-up studies have found that certain aspects of these temperament styles tend to be consistent and enduring throughout childhood and even adulthood (Bates et al., 2014; Sayal et al., 2014). But that is not to say every shy, cautious infant ends up a shy adult. Many events take place between infancy and adulthood that shape an individual's development. Moreover, culture can also influence infant temperament. One recent study found that Dutch babies tend to be happier and easier to soothe, whereas babies born in the United States are typically more active and vocal (Sung et al., 2015). These temperament differences are thought to reflect cultural differences in parenting styles and value
One of the most influential factors in early personality development is goodness of fit between a child's nature, parental behaviors, and the social and environmental setting (Mahoney, 2011; Seifer et al., 2014). For example, a slow-to-warm-up child does best if allowed time to adjust to new situations. Similarly, a difficult child thrives in a structured, understanding environment but not in an inconsistent, intolerant home. Alexander Thomas, the pioneer of temperament research, thinks parents should work with their child's temperament rather than trying to change it. Can you see how this idea of goodness of fit is yet another example of how nature and nurture interact?
Androgyny
One way to overcome rigid or destructive gender-role stereotypes is to express both the "masculine" and "feminine" traits found in each individual—for example, being assertive and aggressive when necessary but also gentle and nurturing. Combining characteristics in this way is known as androgyny [an-DRAH-juh-nee]. Researchers have found that this blending of traits leads to higher self-esteem and more success and adjustment in today's complex society because it allows us to display whatever behaviors and traits are most appropriate in a given situation (Bem, 1981, 1993; Pauletti et al., 2016). Ironically, despite changes in the participation and acceptance of women and men in nontraditional domains, one recent study found that gender role stereotypes are basically as strong today as they were 30 years ago (Haines et al., 2016). Further support of this durability of gender stereotypes comes from a survey of college students at a comparatively liberal university in California. This study found that more than two-thirds of both women and men in heterosexual relationships strongly prefer traditional gender roles when it comes to marriage proposals. In fact, the title of the published research article is: "Girls don't propose! Ew" (Robnett & Leaper, 2013). Furthermore, over 60% of the women surveyed were either "very willing" or "somewhat willing" to take their husband's surname.
PARENTING STYLE Permissive-neglectful(low C, low W) DESCRIPTION Parents make few demands, with little structure or monitoring (low C). They also show little interest or emotional support; may be actively rejecting (low W). EXAMPLE "I don't care about you—or what you do." EFFECT ON CHILDREN Children tend to have poor social skills, and little self-control (being overly demanding and disobedient).
PARENTING STYLE Permissive-indulgent (low C, high W) DESCRIPTION Parents set few limits or demands (low C), but are highly involved and emotionally connected (high W). EXAMPLE "I care about you—and you're free to do what you like!" EFFECT ON CHILDREN Children often fail to learn respect for others, and tend to be impulsive, immature, and out of control.
MATERNAL FACTORS Malnutrition Exposure to: Environmental toxins, X-rays, excessive stress Legal and illegal drugs: Certain prescription drugs, alcohol, nicotine, cocaine, methamphetamine Diseases: Heart and thyroid disease, diabetes, asthma, infectious diseases
POSSIBLE EFFECTS ON EMBRYO, FETUS, NEWBORN, OR YOUNG CHILD Low birth weight, malformations, less developed brain, greater vulnerability to disease Low birth weight, malformations, cancer, hyperactivity, irritability, feeding difficulties Inhibition of bone growth, hearing loss, low birth weight, fetal alcohol spectrum disorders (FASD), intellectual disability, attention deficits in childhood, death Blindness, deafness, intellectual disability, heart and other malformations, brain infection, spontaneous abortion, premature birth, low birth weight, death
Having briefly discussed Vygotsky's alternative theory, let's consider two major criticisms of Piaget—underestimated abilities and underestimated genetic and cultural influences. Research shows that Piaget may have underestimated young children's cognitive development. As we discussed earlier, infants develop concepts like object permanence at a much earlier age than Piaget suggested. In addition, Piaget believed that infancy and early childhood were a time of extreme egocentrism, in which children have little or no understanding of the perspective of others. However, research finds that empathy develops at a relatively young age (Figure 9.17). For example, even newborn babies tend to cry in response to the cry of another baby (Diego & Jones, 2007; Geangu et al., 2010). Also, preschoolers will adapt their speech by using shorter, simpler expressions when talking to 2-year-olds as compared to talking with adults.
Piaget's model, like other stage theories, has also been criticized for not sufficiently taking into account genetic and cultural differences (Newman & Newman, 2015; Shweder, 2011). During Piaget's time, the genetic influences on cognitive abilities were poorly understood, but as in the case of epigenetics, there has been a rapid explosion of information in this field in the last few years. In addition, formal education and specific cultural experiences can significantly affect cognitive development. Consider the following example from a researcher attempting to test the formal operational skills of a farmer in Liberia
3.Possible gender bias
Researcher Carol Gilligan criticized Kohlberg's model because on his scale, women often tend to be classified at a lower level of moral reasoning than men. She suggested that this difference occurred because Kohlberg's theory emphasizes values more often held by men, such as rationality and independence, while de-emphasizing common female values, such as concern for others and belonging (Gilligan, 1977, 1993; Kracher & Marble, 2008). However, most follow-up studies of Gilligan's specific theory have found few, if any, gender differences
2.Cultural differences
Some studies confirm that children from a variety of cultures generally follow Kohlberg's model and progress sequentially from his first level, the preconventional, to his second, the conventional (Rest et al., 1999; Snarey, 1995). However, other studies find differences among cultures (Csordas, 2014; Vozzola, 2014). For example, cross-cultural comparisons of responses to Heinz's moral dilemma show that Europeans and Americans tend to consider whether they like or identify with the victim in questions of morality. In contrast, Hindu Indians consider social responsibility and personal concerns two separate issues (Miller & Bersoff, 1998). Researchers suggest that the difference reflects the Indians' broader sense of social responsibility. Furthermore, in India, Papua New Guinea, and China, as well as in Israeli kibbutzim, people don't choose between the rights of the individual and the rights of society (as the top levels of Kohlberg's model require). Instead, most people seek a compromise solution that accommodates both interests (Killen & Hart, 1999; Miller & Bersoff, 1998). Thus, Kohlberg's standard for judging the highest level of morality (the postconventional) may be more applicable to cultures that value individualism over community and interpersonal relationships.
cross-sectional design
The ___________ measures individuals of various ages at a single point in time to provide information about age differences. For example, one cross-sectional study studied women in three different age groups (ages 22-34, 35-49, and 50-65) to examine whether body weight dissatisfaction changes with age (Siegel, 2010). Unfortunately, female body dissatisfaction appears to be quite stable—and relatively high—across the life span.
germinal period, embryonic period, and fetal period
The vast changes that occur during the nine months of a full-term pregnancy are usually divided into three stages:_____________. Prenatal growth and growth during the first few years after birth are both proximodistal (near to far), which means that the innermost parts of the body develop before the outermost parts. Thus, a fetus's arms develop before its hands and fingers. Development at this stage also proceeds cephalocaudally(head to tail)—a fetus's head is disproportionately large compared with the lower part of its body. Can you see how these two terms—proximodistal and cephalocaudal—help explain why an infant can lift its head before it can lift its arms and lift its arms before lifting its legs?
Deprivation and Development What happens if a child is deprived of appropriate stimulation during a critical period of development? Consider the story of Genie, the so-called "wild child." From the time she was 20 months old until authorities rescued her at age 13, Genie was locked alone in a tiny, windowless room. By day, she sat naked and tied to a child's toilet with nothing to do and no one to talk to. At night, she was immobilized in a kind of straitjacket and "caged" in a covered crib. Genie's abusive father forbade anyone to speak to her for those 13 years. If Genie made noise, her father beat her while he barked and growled like a dog. Genie's tale is a heartbreaking account of the lasting scars from a disastrous childhood. In the years after her rescue, Genie spent thousands of hours receiving special training, and by age 19 she could use public transportation and was adapting well to special classes at school. Genie was far from normal, however. Her intelligence scores were still close to the cutoff for intellectual disability. And although linguists and psychologists worked with her for many years, she was never able to master grammatical structure, and was limited to sentences like "Genie go" (Rymer, 1993).
These findings suggest that because of her extreme childhood isolation and abuse, Genie, like other seriously neglected or environmentally isolated children, missed a necessary critical period for language development (Curtiss, 1977; Raaska et al., 2013; Sylvestre & Mérette, 2010). To make matters worse, she was also subjected to a series of foster home placements, some of which were emotionally and physically abusive. According to the latest information, Genie now lives in a privately run facility for mentally underdeveloped adults (James, 2008)
Aging does seem to take its toll on the speed of information processing (Chapter 7). Decreased speed of processing may reflect problems with encoding (putting information into long-term storage) and retrieval (getting information out of storage). If memory is like a filing system, older people may have more filing cabinets, and it may take them longer to initially file and later retrieve information. Although mental speed declines with age, general information processing and much of memory ability are largely unaffected by the aging process Despite their concerns about "keeping up with 18-year-olds," older returning students often do as well or better than their younger counterparts in college classes.
This superior performance by older adult students may be due, in part, to their generally greater academic motivation, but it also reflects the importance of prior knowledge. Cognitive psychologists have clearly demonstrated that the more people know, the easier it is for them to lay down new memories (Goldstein, 2014; Matlin, 2016). Older students, for instance, generally find this chapter on development easier to master than younger students. Their interactions with children and greater, accumulated knowledge about life changes create a framework upon which to hang new information. In short, the more you know, the more you can learn. Thus, more education and having an intellectually challenging life may help you stay mentally sharp in your later years—another good reason for going to college and engaging in life-long learning
Aging does seem to take its toll on the speed of information processing (Chapter 7). Decreased speed of processing may reflect problems with encoding (putting information into long-term storage) and retrieval (getting information out of storage). If memory is like a filing system, older people may have more filing cabinets, and it may take them longer to initially file and later retrieve information. Although mental speed declines with age, general information processing and much of memory ability are largely unaffected by the aging process Despite their concerns about "keeping up with 18-year-olds," older returning students often do as well or better than their younger counterparts in college classes.
This superior performance by older adult students may be due, in part, to their generally greater academic motivation, but it also reflects the importance of prior knowledge. Cognitive psychologists have clearly demonstrated that the more people know, the easier it is for them to lay down new memories. Older students, for instance, generally find this chapter on development easier to master than younger students. Their interactions with children and greater, accumulated knowledge about life changes create a framework upon which to hang new information. In short, the more you know, the more you can learn. Thus, more education and having an intellectually challenging life may help you stay mentally sharp in your later years—another good reason for going to college and engaging in life-long learning
Research Approaches
To answer these three controversies and other questions, developmental psychologists typically use all the research methods discussed in Chapter 1. To study the entire human life span, they also need two additional techniques—cross-sectional and longitudinal
Schemas
To appreciate Piaget's contributions, we need to consider three major concepts: schemas, assimilation, and accommodation. ______ are the most basic units of intellect. They act as patterns that organize our interactions with the environment, like an architect's drawings or a builder's blueprints. For most of us, a common, shared schema for a car would likely be "a moving object with wheels and seats for passengers." However, we also develop unique schemas based on differing life experiences
ageism
Unfortunately, television, magazines, movies, and advertisements generally portray aging as a time of balding and graying hair, sagging body parts, poor vision, hearing loss, and, of course, no sex life. Can you see how our personal fears of aging and death, combined with these negative media portrayals, contribute to our society's widespread _____prejudice and discrimination based on physical age Sadly, a recent study found that older adults who reported discrimination based on their age had significantly lower physical and emotional health, and greater declines in health, than those who did not report such discrimination (Sutin et al., 2015). The good news is that advertisers have noted the large number of aging baby boomers, and are now producing ads with a more positive and accurate portrayal of aging as a time of vigor, interest, and productivity.
Late Adulthood Brain
What about changes in the brain in later years? The public and most researchers long believed aging was inevitably accompanied by declining cognitive abilities and widespread death of neurons in the brain. Although this decline does happen with degenerative disorders like Alzheimer's disease (AD), it is no longer believed to be an inevitable part of normal aging. Furthermore, age-related cognitive problems are not on a continuum with AD. That is, normal forgetfulness does not mean that serious dementia is around the corner.
As you might expect, authoritative parenting, which encourages independence but still places controls and limits on behavior, is generally the most beneficial for both parents and children . Sadly, research has found a link between permissive parenting and college students' sense of "academic entitlement," which in turn is associated with more perceived stress and poorer mental health among college students (Barton & Hirsh, 2016). Furthermore, authoritarian parenting by mothers and fathers is linked with increased behavior problems
What about the father's parenting style? Until recently, the father's role in discipline and child care was largely ignored. But fathers in Western countries have begun to take a more active role in child-rearing, and there has been a corresponding increase in research. From these studies, we now know that children do best with authoritative dads, who are absorbed with, excited about, and responsive to their children. It's important to note that children do best when parents share the same, consistent parenting styles, but mothers and fathers often differ in their approaches, and research shows that such differences increase marital conflict and child behavior problems
Now that you have a better idea of these two types of research, if you were a developmental psychologist interested in studying intelligence in adults, which design would you choose—cross-sectional or longitudinal? Before you decide, note the different research results shown in Figure 9.4.
Which results are true? Cross-sectional studies have shown that reasoning and intelligence reach their peak in early adulthood and then gradually decline. In contrast, longitudinal studies have found that a marked decline does not begin until about age 60. Adapted from Schaie, 1994, with permission.