Exam 1
standard growth curves
-Age, length, weight -Fan things represent median and then percentiles-->90th percentile- 90 percent of population is above that -These days kids are at the high percentiles. Why? -->Well nourished so grow close to their potential; Standards were developed in the 1950s when kids on average were smaller -If children fell to far below, they would be put into foster care because weren't growing as they were supposed to
picture of twins: one boy and one girl
-Boy is being breastfed and girl is being bottle-fed: girl is malnourished and boy is way bigger--> Subjected to completely different environments as far as their nutrition; Formula was probably watered down and made with bad water
sexual selection
-Darwin -Female choice Example. Peacocks -Male, male competition -Realistic maximum number of how many offspring a woman can have is around 15-20, while a man can have MANY Women have a limited about of offspring with men can have offspring with as many women as they please -natural selection specifically with reference to sexual selection. Used to explain big differences between females and males. Like a peacock: males have colorful feathers, females don't. Happens in two ways Male-male competition or female choice
shoulders
-Difference in shape of shoulders -Monkey longer front to back -Apes bigger side to side like we are
John Bowlby: Attachment Theory EEA
-Environment of Evolutionary Adaptedness -humans today are living in an environment quite different from the one that our ancestors evolved -at first we were hunter gatherers, foraged for food
EEA?
-Environment of evolutionary adaptedness -Term coined by Bowlby -"When he is born, an infant is far from being a tabula rasa (blank slate). On the contrary he is equipped with a number of behavioral systems ready to be activated by stimuli falling within one or more ranges". -Bowlby: "continuous-care-and-contact mothering so readily apparent among the nonhuman Great Apes was not only appealing and consistent with Western presumptions about how "good mother" ought to behave, it fit with his assumption about the homologies between..."
modern human pattern of childbirth evolved in a mosaic (piecemeal) way
-Evolution in different aspects of the body don't all evolve together -Excellent example of the lack of perfection in design--> eyes -Human birth process evolved as a series of tradeoffs that have led to vulnerabilities--> If pelvis gets too big can't walk, if too small can't have children; Risk of injury/death during childbirth -Discomfort at birth has both proximate and ultimate explanations- importance of social support--> When don't have supportive people around them, problems can arise -Hrdy's descriptions of humans as cooperative breeders begins early
Williams and Ness
-Evolutionary medicine- we need to consider the fact that we evolved from an environment that is very different from the one we live in when it comes to health -Mismatch- we evolve in one environment but we are living in a different one so the adaptations that might have been selected when we were living say in Africa (hot, no water, etc) are not what we need today --> preferences for fat and sugar: evolved in environments where they were scarce resources and finding them would have been good for our health
chicken eggs and fish eggs
-Fish eggs are permeable because they are laid in the water -Chicken eggs have a hard shell because they are laid on land
reconstruction of birth in Tabun
-Fragmentary pelvis -Would encase everything in plaster to solidify it→ to get it where they wanted to go --> if chipped at plaster would risk chipping away at bones -now we can play with the specimens digitally
2 measurements of the pelvis
-Front to back and side to side-->If the two ratios are the same they will =1 -If pelvis is flat (front to back is shorter and side to side is bigger)-->Going to be less than 1
the obstetrical dilemma
-Get the big head out of the body -One way to solve it: give birth to babies that are not as far along in the development process
adaptation
-Gould -1970s Gould and Lewontin wrote the Spandrels of San Marco and the Panglossian... -they argue that historical contingency is very important: wrote about the Panda's thumb--> the thumb evolved from a little bone in the wrist and when they got evolved in the adaptation of grasping for bamboo, the thumb grew -spandrels story- architecture --> nose is a spandrel for glasses -type writer story: an adaptation would explain why our keyboard is arranged this way--> because it allows us to type efficiently/faster; history of type writer: keys were arranged to slow you down because if you went too quickly the keys would get caught; QWERTY keyboard slows you down; the Dvorak keyboard- different keys and within a month of training people were typing faster--> but no one ever uses it even though it is better because you would not be able to use it on any other keyboard; why do we have this slower keyboard?--> back in the day when type writers were new every company had a different arrangement; they developed an industry standard by having a contest; they had a race to see which would be the best type writer key board; the winner had a QWERTY keyboard, not because his keyboard was the best but because he was so well trained in using it--> became new industrialized keyboard; Gould uses this as an object explanation--> history doesn't always make it the best at the time, it may have evolved from a different reason...like the keyboard -The result of natural selection --> Moths adapt by being camouflage; Camels adapted to hold a lot of fluids and go a long time without drinking -Cant infer an understanding of evolution by looking at something's present -how we cope with stress in environment
women continue to live for a long time after menopause. Why do we need an evolutionary reason for this?
-Grandmother hypothesis- if you are a women having children, as you get older you can continue to have more children but each time you have a child, the likelihood that you will live to raise that child goes down -->There comes a point where one is better off (more reproductively successful) continuing to have children of my own or taking care of my daughters children
inclusive fitness
-Hamilton says we should measure reproductive success by how your genes are represented in the next generation -->Could have kids or could make sure that people who carry copies of your genes reproduce too→ siblings and cousins -Says true act of altruism occurs when the cost of helper is less than the fitness benefits times the relatedness (C<Br)-->Individuals will treat people differently depending on how genetically close they are -Less likely to chase our their siblings -Reply when asked if he would give his life to save a drowning brother, as quoted in Mathematical Models of Social Evolution: A Guide for the Perplexed-->I would give my life to save 2 brothers or 8 cousins→ 2 brothers have as much genetic material as he does; Natural selection has favored animals who treat their siblings better than they treat their cousins
sex differences in the pelvis
-Has to do with the fact that they serve different functions; has to transmit body weight during locomotion -Females: also has to do lots of other things like let baby pass through during childbirth
The Human Spark- So Human, So Chimp- Chimps vs. Kids
-Human babies and chimp babies just want to help -Chimp babies are limited to only reaching -Human babies seem to enjoy helping -Doing this requires shared attention for the same task (thinking of themselves as sharing an objective with the adult)→ pretty close to theory of mind, maybe they don't even want to do the task but they understand that the adult wants to
child wellbeing in our society vs. others
-In our society, the child's wellbeing is paramount; its needs trump the desires of other family members--> Resource allocation- if strapped for money, the kid is going to get the new pair of shoes -Elsewhere, children may be the lowest-ranking members of the community and may be treated accordingly, for example, being fed on leavings from the adult's meal -In our society we think every child is invested with tremendous inherent worth. We spend millions in enhanced reproductive techniques and millions more on keeping alive even the highest risk neonates -Humans have often abandoned or disposed of surplus of defective babies. Girls are especially vulnerable. Societies develop elaborate customs to legitimate or dignify these practices such as treating an anomalous infant as a changeling. As these practices are venially condemned by moral authorities, unwanted babies were consigned to institutional care where the majority die --> not all societies see babies as we do -From the moment of birth, if not before, we have assigned a high value to the child and make investments of time and resources accordingly -Historically the newborn may have been little valued or viewed as having value except in the future as a helper and later, caretaker of aging parents -The baby is treated as a sentient being from birth, a worthy object of speech and capable of communication non-verbally. In East Asia and among Western elite, the fetus may be seen as responding to speech and music -More commonly, infant provokes mixed emotions and ambiguity. High infant mortality and threats to the mother's life casts a pall. -Each child is a treasure with great emotional value to the new parents. The family fully expects to provide care and resources to each child well past puberty. Our society sees children as precious and innocent, needing protection from the world of adults and exploitative behavior -With the important exception of nomadic, foraging people, children are considered property. Generally, there is the expectation that a child will participate in household economy as they mature. Children of age 10 may be doing full day's work. In many agrarian societies, the child can provide surplus or return on parents investment. Adults may celebrate child's accomplishments as a worker. In industrialized societies, children may be employed. -In our society we create a special environment for kids, regulate aspects of their lives, regulate how and where kids eat and sleep, make adjustments in our lives to make sure kids are happy and entertained o Not the same in other societies -We feed and nourish all children in our societies -In theory we treat kids all the same but that's not the same in every society -Africa and east Asia→ some moms are completely fixated on taking care of children -In a lot of societies, mothers are fixated on making a living so children are passed off to older siblings, grandparents, etc -In American society, relatively recent for children to have chores -In other societies, expected that very young children will be engaged in useful activities
we think we are all emotionally the same but...
-In the article, seems to be a very different form of grief, parent care and instincts -These people are in a very extreme environment where the majority of their children are dying so they don't invest themselves emotionally in the children that they expect to die
growth spurts
-Largest spurts in late teens -Peak height velocity (PHV) -When looking at prehistoric populations only have bones and teeth to look at -Baby teeth erupt over the course of childhood -Over the first 15-18 years of life, the body grows in different ways and at different speeds-->Brain first, Then teeth, Body, Reproductive system (Don't want this to grow before bodies are fully grown→ may not be big enough)
when did these helpless newborns evolve?
-Little sponges that are ready to soak up cultural knowledge (language, customs, emotions, how to walk, how to treat different people in their family, how to function in society) -It's the helplessness of our babies that helps them to be affective little sponges
saltation and stasis: A model of Human growth
-M. Lampl, J.D Veldhuis, M.L. Johnson -Found out that there was periods of stasis and saltation--> Saltation- jump, Stasis- no change -2 to 63 days wouldn't grow at all and then would grow by a considerable amount -So kids are actually growing overnight and the only way you could know this is by measuring them everyday -Arguing that the smooth growth curves we see are just artifacts that there are lots of different data going into them
only thing we have from homo erectus
-Male -Juvenile -Fragmentary -Did a lot of work with it because it was all we had--> made mistakes by doing this -more recently: found a female, adult, fully put together
article (authors?)
-Mothers do not commit themselves emotionally to their babies -Things that are tragedies in our society are brushed off as nothing in their society -Such high rates of childhood mortality because of malnutrition, sickness (diarrhea most common), dehydration, poverty -Can't take babies to work -Living in urban areas -Low rate of stable marriages--> Important for childhood mortalities because of social support, stable marriages mean more alloparental support
Did other bipedal hominids crawl?
-NO -Crawling is likely a very recent evolutionary novelty associated with modern levels of microenvironmental cleanliness and hygiene
neonatal body size
-Newborn size as percentage of mother's size -Gorilla 2.7% -Chimp 3.3% -Human 6.1%
historical contigency
-Panda's thumb -the paths that life can evolve on are constrained by historical events that are often random
bees
-Queen -Worker -Drone--> they are clones of the queens DNA, do not reproduce
Why would a behavior evolve (can only happen by natural selection) that benefits individuals other than the one who performs the behavior
-Reciprocal altruism- I do something for you, you do something for me -->Might not be an exchange -- not keeping track like in a financial trade -Inclusive fitness- we shouldn't just think about improving our own reproductive success; we should behave in a way where it seems we care about the reproductive success of those who carry our genes
weaning foods
-Some societies have weaning foods -In our society, weaning foods are pureed/ground up foods -Same in some other societies: porridge, pre-chewed food
Causes of behavior: why does a mother react to a crying, hungry infant by picking her up and breastfeeding?
-Survival of infant-- ultimate or phylogenetic cause (relating to the evolutionary development)--> Natural selection has favored this because increases chances of survival -That's the way mothers in her culture respond to crying- ontogenetic --> Ontogeny- growth and development -Crying causes secretion of oxytocin which initiates let-down reflex -Emotional feelings for infant- ontogenetic (emotional) -Crying is irritating to her and others so she wants to stop annoying stimulus-- proximate or environmental
what determines the timing of birth?
-The timing of birth happens when the baby is getting so big that it is not going to be able to fit out of the birth canal → not really the proximate cause -->Proximate cause- close; Ultimate cause- far
Hrdy's critique of Bowlby
-There is no one, universal pattern of infant care among primates -Continuous care to care -Hence for Hrdy: it takes a village
newborn brain size estimated for extinct humans
-What percentage of adult brain size was present at birth -Modern pan -->40% included -Humans--> Smaller as a percentage of what they are going to be; Our brains have to roughly triple; More of our brain growing has been pushed to after birth
developmental milestones
-When your kid should be able to do something • Details of walking, talking, crawling -Then plots to see if your kids are keeping up with the standards -General trajectory of babies are the same but details might be different
recently discovered new fossils from Africa
-Wondered what birth would have been like -Small brained humans but some indications in the pelvis that we thought were related to big brains (big heads)
Infant Carrying and Pre-Walking Locomotor Development: Proximate and Evolutionary Perspectives: David P. Tracer
-Worked with population called AU and studied crawling. Was looking at if crawling was an inevitable stage -"Although physical anthropologists have been studying and documenting somatic growth patterns in non-western populations for a century or more, virtually no research in anthropology has been conducted on neuromuscular and motor skill maturation outside of western context" -Says neuromuscular and motor skill attainment are widely assumed to proceed in a predictable sequence and rate- i.e., according to U.S. an European norms -Looking at something that we assume is natural in our culture is worldwide -One of the most commonly used developmental milestones used by behavioral scientists is crawling -The national Academy for Child Development: o "The first step in detecting neurological disorganization is to evaulatie the child against the developmental profile and to have him tested to rule out the possibility of an organic problem. NACD's evaluation of these children begins by determining the organization at the brain level of the pons--> All kinds of people will children who worry if their kids are crawling at the right time -Crawling is assumed to be a necessary prerequisite to the development of: o General bipedal motor skill development o Eye-hand coordination o Vestibular processing o Attainment of balance and equilibrium o Visual-spatial awareness and processing o Kinesthetic/tactile awareness and processing o Social maturation -Crawling is neither a ubiquitous nor normative pre-walking developmental stage among present populations -Crawling was not a normative part of development throughout human evolution -Crawling is a recent evolutionary novelty -Papua New Guinea: o Where he works o Planting crops and farming but in a very small scale o Foraging→ people carrying things through long stretches of space o Data collected from 113 Au infants and toddlers (0-30 months) • Age • Sex • Birth order • Weight • Recumbent length • Head circumference • Mid-upper arm and maximum calf circumferences • Triceps skinfold • Bayley Motor Scales of Infant Development II • 4 to 6 hour focal follow of infant/caretaker dyads -The Bayley Scales of Infant Development o Apply western ideas to people in New Guinea -Relationship between child's age and Bayley motor development index (MDI) o No consistent trend, correlation is poor -% of Bayley Gross Motor Tests Failed in Horizontal vs. Vertical Posture by Gender o These tests didn't work that well with New Guinea children; they were not developing until the first 30 months o Summary: Au children fail a majority of motor tests administered o Why? --> Kids are always carried around in a vertical position -% Time Carried and Identity of Carriers Among Au Offspring (n=68) Aged 1-12 months o Usually carried by mother or other o Spends least amount of time on ground -Is Papua New Guinea a bizarre aberration or is there something normative (and possible adaptive) about high degrees -Standard regression coefficients of diarrheal risk among 185 Bangladeshi Children aged 4-27 o Positively correlated and negatively correlated --> • Garbage in play area, Child touches garbage, etc -In order to limit oral to ground contact and exposure to pathogens (and predators), high proportions of time spent carried have likely been adaptive and normative for most of human evolutionary history -Even our closest non-human primate relatives follow this pattern (apes and gorillas)
sociobiology
-a field of scientific study based on the hypothesis that social behavior has resulted from evolution- it attempts to examine and explain social behavior within that context -what would it mean for a behavior to evolve?--> for something to evolve it would have had to have a genetic basis
what does Hrdy think is special about humans?
-ability to have mutual understanding -cooperation
human exceptionalism
-art -music -humans are different from all other animals
attachment theory
-attachment theory is between parents and offspring -used to have this strong idea that there was this critical period for bonding and if that opportunity was missed, you would not be able to make up for it
adulthood is signified differently in different cultures
-bar/bat mitzvahs -celebrate the first period -sweet 16s -first kill signifies adulthood
what do you need to have a baby?
-bed sheets, bottles, diapers, apps, strollers (different views on this) -people in our culture think that we can make a list of everything we need
Lucy
-bipedal but small brained person whose birth was under different types of constraint -flat at inlet, midplane, and outlet
what is human brain anatomy constrained by?
-bipedalism and encephalization (big brain), but not only by them -Need to consider neonatal body size, infant maturity at birth, shoulder breadth
what is needed for children to be successful?
-children have to be intellectually stimulated all the time -Show pictures, read to them
what do humans have in common?
-common a biological developmental process that we go through that is probably species typical -We think of certain things like the terrible 2s and the teen years as being inherent to these categories→ we impose these categories
males are bigger risk takers. Why?
-competing with each other for opportunity to mate
crying
-cross cultural variations -infant controls mother
2 important perspectives of anthropology
-cross-cultural -evolutionary
anthropology includes:
-cultural -biological -archaeology -linguistics
precocious
-developing ahead of time; long gestation length; comes out further developed -40% of yolk in egg- lots of energy needed to produce, nests on the ground, open eyes, down/feathers present, leave nest within 2 days, can move around
polygyny threshold
-happens with birds -many females -mating system in which there is one male and many females -would rather share good territory with another female than be the only one at a bad territory
advancement factor
-how long they have come to adulthood -example: growing of brain when born
exterogestation
-humans can give birth to helpless babies because we can do a good job of taking care of them; because we have a cultural womb -cultural womb--> swaddling with blankets -add a cultural solution to a biological problem -human adaptation is to be cultural--> wouldn't be able to survive without culture
humans are apes
-if you look at our closest relatives, they are chimps -we are closer to chimps than either are to gorillas -People want to study chimps because something we share with chimps is probably true of the last common ancestor and people started to think of chimps being just like that ancestor (we have reasons that prove this is not true)--> if we have had 6 million years to evolve from the common ancestor, then so have chimps
Louis Leakey
-looked for evidence of "early man" -for many years just found archaeological evidence and then finally started to find remains
why do some animals eat the placenta?
-maybe has a lot of nutrients -one way to get rid of it in order to keep predators away
to improve reproductive success
-men can mate with more females -females can choose among the available men to get best results--> females invest much more into each offspring
evolutionary medicine
-mismatch- really powerful way of looking at human health and disease; came from the idea that when we think about manifestations of disease we should think about what caused it in terms of evolution -Example: when you have a fever you ache or have a headache, etc. People might take medicine and then you feel better. A fever is our body trying to fight off an infection. Our body has a very small range of body temperatures that are good for us. By lowering your body temperature with medicine you are counteracting your bodies' ability to lower temperature
males have higher mortality rate. Why?
-more likely to be killed in car crashes because they are bigger risk takers on average--> more likely to drive fast, in more dangerous ways -violence is greater in young men -have jobs that put them at higher risk
vision
-newborn babies prefer to look at faces (even in babies less than 10 minutes old) -infants following with eyes encourages maternal care-taking response -at birth focus is 12 in- approximate distance from infant eyes to breast -eye contact
theory of mind and intersubjectivity
-other people see the world differently than we do and have different perspectives -example of 3 year old-- she thinks what she knows is what everyone knows
eugenics
-practice of improving genetic material over time; by controlled breeding we can make the human species better -sterilization
sucking
-rotting and searching for the nipple is common neonatal response in all mammals -soon after birth infants turn heads in response to tactile sensation -nutritive and non-nutritive suckling (non-nutritive has calming effect-- communication)
altricial
-short gestation length, helpless -25% of yolk- less energy needed to produce, nests in trees, caves, on poles, closed eyes, naked very few or no feathers, cannot leave nest, Cannot move around, Cannot feed themselves, Cannot maintain their body temp, Parents have to protect them from predators, Need a lot of parental care for amount of time
are there benefits to eating the placenta?
-some say there are -prevents against postpartum depression?
Margaret Mead
-something about our bodies that makes us react a certain way --> wondered if that was true about all cultures -studies adolescent girls and discovered that they were not stressed at all -says that we shouldn't assume that adolescence is a period of difficulty and conflict
human uniqueness
-spoken language -occupy all continents -we use fire -theory of mind
eusocial
-truly social -live in groups with overlapping generations -alloparental care--> other than parents -division of labor with respect to reproduction-some helpers never breed -insects--> only one member of group reproduces at a time
smiling
-universal? instinctual? -week 5 or so
other species and us
-we are not the only ones that use tools--> monkeys use stones to open fruit -we are not the only ones who walk on 2 legs (only one's who do it that are primates) -not the only ones with language
menarche
-when girls get their first period -Used as a marker of when people matured because it is an event that people particularly remember
Edward Wilson
-wrote "Sociobiology" -question he was addressing was how was the sterile castes (don't reproduce) of insects evolving--> bees, etc -studied altruism--> acts that truly seemed to be selfless (did not expect anything in return)
Effects of Environment on Growth and Development
Boas showed that when families come from places where they were experience economic hardship and come to areas of economic success, the bodies change from generation from generation --> Particularly head shape
secular trends
Changes that occur from one generation to the next that are not evolutionary, accounted for by living conditions
Alice Roberts and Michael Tomasello: What Makes Us Human?
Cooperation more important than some of these other things
Gould
Just because you see something in nature you can't assume that is the reason it evolved
childbirth
Lying down during childbirth only happens in about 16 cultures (12%) -The way it typically happens in the US is not the norm around the world -Shape of the birth canal is different in different species--> humans have a deep curved tube; other species: shape stays the same throughout, shallow bony ring -in general, bigger animals have longer gestation periods -mammals that are born in the water are usually born tail first -in humans, occiput of the skull is to the front of the mother's body
shoulder dystocia
Shoulder dystocia is a specific case of obstructed labour whereby after the delivery of the head, the anterior shoulder of the infant cannot pass below, or requires significant manipulation to pass below, the pubic symphysis. It is diagnosed when the shoulders fail to deliver shortly after the fetal head.
rotational birth
That baby is in that tight fit and typically does the set of turns which is what we have argued makes humans benefit from having someone assist during birth→ allowed people to have bigger brains
post modernism
a late-20th-century style and concept in the arts, architecture, and criticism that represents a departure from modernism and has at its heart a general distrust of grand theories and ideologies as well as a problematical relationship with any notion of "art."
populations are very different
average Brazilian kids are at the bottom 5%
what are human babies oriented towards?
faces--> spend a lot more time looking at faces, information being exchanged (mutual understanding)--> need a third party independent evaluator to see if this is actually the case
humans benefit from assistance during pregnancy
higher reproductive success
the lines in teeth...
is where the enamel was forming at the time when the stress was taking place so you get slowed down growth and when it speeds up you get this line of concentration→ ways we can measure stress in archaeological samples
whose reproductive success is more variable?
male
what has been favored by natural selection?
maternal instinct
What might make maternalness lower?
no alloparents
what does the obstetric challenge on the human pelvis come from?
not only from an increasingly large human brain, but also from the changing mechanism of birth as well as other mechanical and developmental constraints, mediated by culture
Thinking about childhood/gender archeologically
o Men were assumed to be doing the important things, higher status, had power o Men are the ones who used things that got left behind o Men's activities were seen as more important
Conclusions: The Current Study Suggest that:
o Motor development is responsive to variability in general nutritional and growth status o The course of neuromuscular development is strongly conditioned by infant-handling behaviors and carrying o Quadrupedal crawling is neither a ubiquitous locomotor stage among humans nor is it a necessary prerequisite to bipedal locomotion o The western "normative" sequence of neuromuscular and motor development is not applicable outside of the western context o Crawling is likely a very recent evolutionary novelty -why does this matter? --> crawling is fine if you live in an environment where kids won't pick up a pathogen/sickness; not necessary to get to the next stage: walking; looking beyond our cultural experience we can give us a lot of information to conform our experience or opinion on what we expect to be the norm
Who usually studies infant sleep?
o Neurologists, pediatricians
asymmetry between males and females
original contribution from men and women are uneven (men--> 1 sperm, women-> eggs)
alloparenting
parenting done by someone besides the biological parents
what do we impose on childhood?
social and cultural gender categories
what happens if the environmental circumstances are different from typical?
the chances of maternalness being successful are lower
anthropology
the study of humankind, viewed from the perspective of all people and all times
secondary altricial is very misleading
we are somewhat more helpless than precocious species in some ways -our reproductive strategy looks like precocial but our infants resemble altricial infants -basically precocial except for being "helpless"
males die earlier than females. Why?
women go to the doctor more