Mod. 7 Lectures 6-9
Mod. 7 Lectures 6-9 ASM 104
Popular in Bones, Stones/Human Evolution
Popular in anthropology, evolution, sphr
This 7 page Class Notes was uploaded by Gabrielle Hsu on Thursday October 8, 2015. The Class Notes belongs to ASM 104 at Arizona State University taught by Campisano in Fall 2015. Since its upload, it has received 41 views. For similar materials see Bones, Stones/Human Evolution in anthropology, evolution, sphr at Arizona State University.
Reviews for Mod. 7 Lectures 6-9
-Claudia M Alvarado
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 10/08/15
MODULE 7 LECTURE 6 INTRODUCTION This lecture is about evolutionary psychology It discusses the evolution of the human brain amp behavior KEY POINTS Reasons for controversy around human behavior being evolved Tendency to think of humans as quotspecialquot different from other animals Can con ict with religious beliefs Nature vs nurture fallacy Says that behavioral traits are learned amp determined by the environment so it can t evolve It s true that specific behaviors are adaptive amp don t evolve directly but brain mechanisms that affect learning do evolve MAIN IDEAS Examples of evolved learning mechanisms Food aversion Rats remember all the foods they eat for about 12 hrs amp if they get sick they associate it w whichever food was new different amp don t eat that food anymore Stellar navigation Indigo buntings small migratory bird observe how stars change position amp know that north is towards the center of rotation Origins of evolutionary psychology Evolution takes a long time especially for complex traits like learning Egt most human brain mechanisms must have evolved a long time ago Egt a long time ago 10000 years humans lived in foraging societies Egt most human brain mechanisms are probably based on problems had people in foraging societies had Examples Mate choice Inbreeding avoidance Selected against bc creates higher chance of passing on harmful recessive genes Mechanism in most primates members of one sex usually male leave their natal group when sexually mature preventing inbreeding Most modern human societies forbid inbreeding not common in any Probably due to this evolved mechanism Evidence Lack of sexual desire between individuals raised together Ex much higher rates of infertility amp divorce in minor marriagesquot where marriage is arranged amp bride joins groom s family as a child earlier joining lower fertility Reproductive success People choose mates most likely to reproduce successfully Prediction men focus on youth good looks bc women have earlier shorter reproductive prime women focus on ability to provide for offspring Research results these are true in most cultures but to varying degrees In a recent survey of most important traits in a partner most people ranked mutual attraction amp character traits like dependability maturity etc much higher than good looks amp finances Conclusions these traits are important bc they allow people to form successful partnerships to care for offspring Cultural differences certain traits like chastityvirginity are considered unimportant in some cultures but very important in others MODULE 7 LECTURE 7 INTRODUCTION This lecture is about human evolution and culture MAIN IDEAS What s unique about humans Adaptability Largest range almost the whole world of any terrestrial species even thousands of years ago wolves have the next largest range but only occupy Eurasia amp N America Fast adaptation modern humans took only 40 thousand years to spread around the world after leaving Africa How is this is possible Are humans smarter than other animals Steven Pinker The cognitive nichequot Yes humans are quotsmarterquot in certain ways reasoning understanding others etc but not individually smart enough to solve all of the problems needed for this rapid adaptation Example Inuits survive cold climate by making clothes from caribou hides amp sinews snow houses soapstone lamps w seal fat amp moss wicks etc One person couldn t figure all of this out on his own Sir John Franklin British explorer led an expedition to northern North America they all died bc they didn t have the generations of knowledge that the Inuits do which has to do with imitation Role of imitation does it increase adaptability Example population where some individuals are learners amp always learn the behavior that increases fitness most while others are imitators who randomly imitate other members If there are few imitators their fitness increases bc they imitate learners amp have the best behaviors wo the effort of learning them BUT higher fitness means their frequency increases amp they start to imitate other imitators who imitated other imitators etc gt they no longer consistently have the best behaviors if nobody studies for a test amp everybody cheats everybody fails Adaptability ONLY increases if imitation happens in a way that increases fitness of learners Selective learning imitating only if it takes too much effort to learn on your own Accumulated improvement improvements can be passed down to the next generation through culture amp continue to be built on instead of everyone starting from scratch MODULE 7 LECTURE 8 INTRODUCTION This lecture continues the topic of the last lecture human evolution and culture KEY POINTS Humans can evolve faster than other animals because they pass down knowledge through generations accelerating adaptation For this to work people have to be selective learners meaning they figure out easy problems themselves amp rely on other people imitation for hard problems MAIN IDEAS Negative effects of imitation Requires people to believe rely on other people gt spread of ideas that natural selection wouldn t favor maladaptivequot ideas How this happens Imitation isn t perfect each time someone imitates the result is affected by his own cognitive biases differences in perception amp this effect is amplified over time like the game of telephone Content bias believing information that is slightly unlikely or counterintuitive because it is more memorable like stories of supernatural encounters Prestige bias imitating famous successful people if those people have maladaptive behavior other people will imitate it What else is unique about humans Cooperative behavior benefits others but costs self frequent in humans rare in other animals Common even in simple huntergatherer societies Data men aged 2060 produce much more than they consume younger or older consume more than they produce After weaning chimpanzees all produce amp consume the same amount Caring for sick injured disabled Happens even in earlyprimitive human societies but not in other mammals Large war parties even in seemingly disorganized societies Ex Turkana Kenyan herding group w no formal government In cooperative societies what stops freeriders In most mammals individuals cooperate w others who are related to them so freeriders are selected again bc their behavior also damages their relatives Humans cooperate w others who are not related w them so there are other mechanisms Norms enforced by reciprocity reputation amp retribution Faster adaptation gt stronger amp more varied norms gt intergroup selection one group outcompetes another bc its cultural norms make it more effective at something like warfare gt spread of the more successful group s norms Norms can also spread through imitation or by people choosing to join groups w norms they prefer oWhat this doesn t explain If this is beneficial why doesn t it happen in other species Retribution could also enforce noncooperation Selfdomesticationquot of humans Very long evolutionary trend towards more cooperative traits Example white sclera area of eye surrounding iris Almost all other mammals have a dark sclera including other primates the light sclera makes it easier for others to tell what you re thinking planning which is a good trait in a cooperative society MODULE 7 LECTURE 9 INTRODUCTION The last one This lecture focuses on human mating marriage amp parenting KEY POINTS Marriage system cultural norms around who can marry each other divorce etc Different from a mating system which describes sexual behavior MAIN IDEAS History of marriage About 3A of historical human societies allowed polygyny one man marrying more than one woman but in many of these it wasn t actually that common bc most men couldn t support multiple wives Agriculture gt more complex societies w large wealth gap gt rich men could afford to have many wives amp it was viewed as a status symbol Now modern societies are complex amp have even bigger wealth gaps but most marriage systems are monogamous Spread from Greece Mesopotamia to Rome to the rest of Europe to the whole world except some Islamic amp central African cultures Why is monogamy favored when it seems contrary to natural selection Men could increase chances of reproductive success by having more wives Women are more likely to be successful as one of many wives of a rich man than as a poor man s only wife Cultural evolutionary hypothesis for monogamy Reduces intrasexual competition which can be bad because 0 A few rich men marry lots of women gt fewer women available for other men gt those men do risky destructive things crime to gain enough wealth status to get married 0 More competition for wives gt more resources invested in getting wives gt less resources left to invest in children These aren t big problems in agrarian societies bc young men are usually in the military so angryviolent unmarried men have a constructive purpose Parental investment is not as important as it is in complex modern societies where they need to provide for education etc Benefits of reduced competition less crime con ict more educated youth more economic growth led to spread of monogamy Evidence for this hypothesis Correlation between of unmarried men amp rates of rape murder amp fraud found in study of multiple countries Study following men from age 17 to 70 found the same person was 35 less likely to commit a crime when married rates were higher before marriage amp higher after divorce or widowing China 1child policy male to female sex ratio rose from 105 to 109 gt twice as many unmarried men gt crime rate increased in correlation Higher childhood mortality in polygynous societies due to less investment in children rich men have multiple wives amp more children so resources are diluted amp have had to invest more in their wives bc of competition for them Higher GDP in monogamous societies than polygynous Probably spread by poorer less successful polygynous societies adopting more successful countries norms or being conquered by those countries Parenting Prediction parents evolved to want to give lots of care to children because human infants can t survive on their own amp need to be provided for Conclusion this is true although families have different size structure every human society has them Exceptions Infanticide Prediction should occur when parents don t want to invest in the child bc for some reason lack of resources single parent etc it s unlikely to survive and or reproduce Results survey of 112 societies found most common reasons for infanticide were the child is deformed ill parents can t care for it or it wasn t fathered by the husband Adoption Prediction evolutionarily unlikely bc raising someone else s children reduces resources you have for raising your own Results extremely rare in any other species but very common in some human societies Most children are adopted by relatives this raises the adoptive parent s inclusive fitness Reasons Parents can t raise the kids dead disabled lack of resources etc Adoptive parents can t have their own kids sterility Cultural differences between Oceania amp US More adoption of unrelated children in US Adoptees in US less likely to know amp have contact w birth parents Less equal care for adopted children in Oceania disadvantaged compared to birth children