Exam 2 Flashcards
What is optimal foraging theory? How successful is it in explaining foraging patterns?
- natural selection designed humans to maximize their rate of energy return relative to the amount of time they spend foraging
- research shows ppl make rational decisions much of the time - stop collecting a resource when it reduces the average rate of return for all resources combined
According to optimal foraging theory, what is search time, handling/processing time, opportunity costs?
- search time: time it takes to search for plants and animals to eat
- handling/processing time: time it takes to dig up,cut down plants, get them ready to eat; also includes time spent tracking, killing and butchering animals
- opportunity costs: time spent searching for one type of food leaves less time to find other types of food
What are the exceptions to optimal foraging theory? Do they make sense in light of evolution?
- strong preference for meat
- sometimes men pass on plants to hunt for game, even when rate of return is lower
- evolution explan: nutritional advantage to meat, way achieve status (hunters tend to have higher status leading to better mating opportunities)
What are the strategies ppl use to “make a living”?
- hunting/gathering: exclusive until about 10,000 yrsa ago, bands of no more than 100 individuals, frequent move camps, food storage rare
- cultivating crops
- herding animals
- making goods and selling them
How often do hunter gatherers move camp? Why is there variability in this?
- varies, depending on the region they inhabit (ex. 50x a year vs. 2x a year)
- also changing of the seasons and what resources are available to them
What percent of food comes from hunting? Gathering? How does it relate to latitude?
- latitude relates to the availability of diff types of food
- closer to equator about half from gathering (50-60ish)
- further from equator much more than half from hunting/fishing
- as latitude increases, reliance on hunting and fishing increases
In hunter-gatherer societies, who hunts and who gathers? Why?
- men do hunting, women gather
- why women don’t hunt: women much more important to survival of offspring (carry child, feed child, pregnancy) takes them away from child for period of time
What are the benefits of being a good hunter?
- aside from the nutritional advantage
- good hunters (men) have higher social status and are preferred as mates
What is the Provisioning Hypothesis?
- transition from foraging to large game hunting provided major impetus for human evolution including toolmaking & use, development of large brains, complex language used to communicate w/ other hunters
- meat is full of energy, benefits brought to men who provide meat for their families
What is the support for the provisioning hypothesis/ what does it explain?
- strong male coalitions
- reciprocal altruism & social exchange: help someone at cost to yourself and they may return the favor at another time
- division of labor: better for women to be with young children
- emergence of stone tools
What is the Showoff Hypothesis? What support is there for this idea?
- hypothesis: women prefer to have neighbors who are showoffs (go after rare large game, women benefit by getting some of the meat)
- women reward men who do this by favoring them, siding with them during disputes, having sex with them
- not all men good at hunting; takes years to perfect
- good hunters are preferred by women (higher social status preferred as mates; women may withhold sex if male doesnt bring home meat)
What is the Gathering Hypothesis? What is the benefit of this view? Can it explain as much as the provisioning hypothesis?
- hypothesis: securing plant food through use of stone tools provided the primary evolutionary impetus for the emergence of modern humans (hunting became important later)
- corrects view that centers solely on men
- accounts for primate relatives having diets coming mostly from foraging
- does not account for division of labor
Is the claim that hunter-gatherers are “affluent” (meaning they don’t have many needs) true?
- not true
- spend about 28 hrs foraging
- about 46 hrs a week of work (making/repairing tools/weapons, processing foods, fathering wood)
- ppl undernourished
- food anxiety
- high infant mortality rate
- infectious disease
When and where did agriculture develop? What plants and animals were domesticated?
- about 10,000-11,500 yrs ago in fertile crescent
- wheat, barley, rye, peas, lentils
- sheep, goats, cattle, pigs
What’s the possible adaptation for being sick during pregnancy?
- nausea & vomiting give protection from harmful effects of toxins and pathogens (vomiting expels pathogens; nausea learn to avoid)
- also encourage to avoid pathogenic food
What foods have the highest aversions for pregnant women?
- meat, eggs, coffee, alcohol, broccoli, brussel sprouts, cabbage
When are women sickest? What is the significance of this?
- sickest during 1st trimester
- significant bc fetus very vulnerable in this stage and mother’s immune system is vulnerable in this period (suppressed)
- progesterone stimulates decrease in NK cells
Do women feel only heightened disgust or are some good smells heightened as well?
- increased olfactory acuity overall
- find some odors less pleasant
- find some odors like fruit and flowers more pleasant
Why do moms lower their immune system during early pregnancy? What impact does this have on pregnancy sickness?
- early on immune system is suppressed bc body interprets fetus as foreign body therefore suppresses immune system to keep from attacking
- immune response at lowest level when women experience sickness
What does cross-cultural evidence show about pregnancy sickness?
- sickness appears to be widespread; in some cultures is the first outward sign of pregnancy recognized
- lower levels of sickness in places that eat less meat (meat often contains toxins)
Why are babies born so early?
- large heads have to fit through woman’s pelvis
What is altricial?
- at birth young are poorly developed; helpless
Why is the human pelvis so small?
- bc of bipedal locomotion
Why is it that food in lower latitudes is more spicy?
- spices used in places where food spoils more quickly
- spices help to kill bacteria
What is the function of disgust?
- disgust at potentially dangerous substances may keep us from getting sick
What is behavioral prophylaxis?
- we perform behaviors to avoid diseases
- these behaviors prevent illness
Explain the Red Queen Principle
- another phrase for evolutionary arms race
- fitness increase in one evolutionary system tends to lead to fitness decrease in another system
- only way that a species involved in a competition can maintain its fitness relative to the others is by in turn improving its design
What is an evolutionary arms race?
- co-evolution between organisms in conflict
- ex. hosts & parasites, predator & prey
What do humans do to increase pathogen virulence? How can we reduce the virulence of pathogens?
- we put evolutionary pressure on microbes for them to evolve and become more resistant
- force pathogens to spread through routes that make them less severe
What is the general function of emotion?
- adaptations shaped by natural selection
- specialized - help us to respond effectively
- protect us from harm (ex. disgust keeps us from ingesting dangerous substances)
What is the information threat theory of shame?
- shame evolved to manage the recurrent threat of devaluation due to adverse info reaching others
- status within a group is important - valued individuals receive help while being less valuable others may seek to harm you & give less help
What does shame motivate people to do?
- social withdrawal
- accept subordination
- appeasement behavior
- more cooperation
- nonverbal display
What things are most shameful?
- things that others view as most negative
What is the function of anger?
- a bargaining tactic to resolve conflicts in favor of the angry individual
- 2 negotiating tactics of inflicting costs and/or withholding benefits
From an EP perspective, what function does anxiety serve? Why do levels change? Is lack of anxiety a disorder?
- in face of a threat, anxiety alters thinking, behavior, and physiology in advantageous ways (fight or flight response)
- changes bc uses calories & energy, potentially damage tissue
- lack of anxiety may cause ppl to get into dangerous situations (death)
What might depression signal?
- signals maladaptive behavior
What is costly signaling theory? What is an honest signal?
- elaborate displays evolve as honest signals about underlying phenotypic & genotypic qualities of their bearers
- honest signals give off info which increases fitness of receiver (these signals may be costly so that individuals can only produce them when they are “fit”)
What is the function of humor?
- promote bonding
- facilitate cooperation
- signal of being non-threatening
- court mates
What does it mean that humor may be sexually selected?
Who prefers humor and why?
- may reveal good genetic qualities (reveals intelligence, creativity)
- related to IQ
- humor increases men’s attractiveness, and men like women who appreciate their humor
What is the function of maternal love?
- motivates caring for helpless child
According to Buss, why are ppl so unhappy?
- 1.) discrepancies between modern and ancestral environment (used to live in large groups now in nuclear families making us feel isloated/lack social support)
- 2.) modern environments appear to negatively impact how we feel (more self-perceived failure bc of media and less satisfaction w/ partners bc of media)
- 3.) there are adaptations that cause distress (many neg emotions helps us solve adaptive problems of social living)
How can understanding the evolution of emotion improve happiness?
- 1.) close the gap between modern & ancestral conditions (closer contact w/ kin; develop deep friendships)
- 2.) reduce subjective distress (finding similar mate; being near extended kin reduces likelihood of incest, child abuse, dom violence, etc.)
- 3.) managing competitive mechanisms (promote cooperation)
Explain the Social Navigation Hypothesis for depression? (REH)
- depression is triggered by complex social problems that altered fitness
- 1.) social rumination helps find solutions to social problems
- 2.)extortion of group members increases help given by group
- 3.) honest signaling elicits aid from social partners
Explain the Analytic Rumination hypothesis for depression?
- depression is triggered by analytically complex fitness related problems
- depressive symptoms help solution analysis which equates to an unrelenting investigation of the problem
- helps solve fitness related problems
Explain the social risk hypothesis for depression
- depression is triggered by negative social solutions that may cause group exclusion or low group value
- reduces risk taking behaviors to maintain group membership
- increases interpersonal sensitivity and submissive behavior
Explain Trivers theory about parental investment and sexual selection
- differences between men and women in the minimum levels of parental investment drive sex differences
- the sex that invests more (women) tend to be choosier selecting mates
- sex that invests less tends to compete more for mates; less choosy; prefer signals of fertility
Why do sex differences exist at all?
- sex is defined by the size of the sex cells and individual possesses (women have few large eggs,men have many small mobile sperm)
Do men or women prefer more sex partners? How bug is the difference at different time points (month vs lifetime)?
- women max. about 5 partners lifetime (one or 2 a month)
- men 2-3 a month, max lifetime about 17
How much difference in age of spouse to men and women prefer? How does this vary across cultures?
- in US women prefer spouse 2 yrs older, men prefer 2 yrs younger
- overall men prefer younger spouses, women prefer older
- some cultures prefer a much wider age gap
What is sexually antagonistic coevolution? What evidence supports this?
- things that optimize one partner’s outcomes do not match those that optimize the other partner’s outcomes
- similar to Red Queen Principle but specific about sexual competitions within species adaptations
- Rice’s fruit fly study: males allowed to evolve while females weren’t, so male fitness increases and had higher reproductive success; while female fitness decreased
What characteristics do women prefer in a long term mate?
- men who are able to invest
- high social status, older age, good financial prospects
- dependable, loving, committed
- compatible with similar values and personality
- good parenting skills
