Psych 3F03 Midterm 2

cross species differentiation

species have different traits because they need different things for success in different enviros

life history theory

analytical framework that attempts to explain and predict variation in life history cycles, specifically related to reproduction and lifespan, can help predict phenotypic expression on a variety of traits

life history strategies: fast vs slow

fast associated with early reproduction and shorter lifespans, slow associated with later reproduction and longer lifespan

r selection

fast

k selection

slow

r selected species

faster growth patterns, earlier sexual maturity, shorter lifespan, fewer but larger reproductive events, minimal parental care so low offspring survival

k selected species

slower growth patterns, later sexual maturity, longer lifespan, fewer offspring at a time but more reproductive events happen across lifespan, high parental care and offspring survival

r and k selection: type i, ii, iii

r and k is type i and ii, most species are type ii

enviro factors help determine strategy

2 key: unpredictable events → when resources and mate availability, survivability are unpredictable species are more likely to take a fast or r selected strategy and harshness → harsher enviros are associated with fast life history strategies

reproductive optimization

natural selection encourages, populations that evolved fast or slow have done so due to selection pressures

mating strategies depend on:

sex ratio/ partner availability, dominance status, development, enviro changes

within species variation

for species where populations have varied enviros like humans, unpredictability and harshness plays huge role

big data research supporting variation in life history strategies

investigated early reproduction based on unpredictability and harshness, unpredictability (like loss of parent and moving) affected more than harshness

risk of enviro adversity with reduced future thinking

priming participants with images of harsh enviros increases present- oriented thinking, individuals from poorer enviros prefer immediately rewarding jobs rahter than potential long term benefits

mortality cues affect people based on upbringing

engage in gambling, show participants newspapers articles that heightened awareness of mortality or didn’t, compared high and low ses backgrounds, mortality prime increased fast life history decisions in individuals with low-SES backgrounds, but did the opposite in individuals with high-SES backgrounds

marshmallow test results

kids who waited outperformed kids who didn’t in almost every life outcome measure, however recent study shows this effect is based on ses and family stability… reality poorer children likely to eat first and can be understood from life history strategy… more likely to engage in present- oriented thinking so later life outcomes likely indicative of early life ses rather than performance on task

anisogamy

when males and females have dissimilar gametes and dissimilar investment into reproduction (sexual dimorphism seen in animal kingdom)

sexual dimorphism

2 major: optimal mating rate and amount of competition for access to mates

sexual conflict

when males and females have different strategies for optimizing their reproductive fitness

sexually antagonistic coevolution

male exploitation (any behavior to get females unrelated to genetics) vs female resistance (traits that evolve in response to protect from male harassment) (keep in mind exploitation reduces female fitness and female resistance reduces male fitness)

fruit fly and sexual conflict

testing behaviour and fitness of flies under strict monogamy or natural polygamy for 47 generations: males forced to evolve under monogamy to harass females less and as a result females have higher fitness (recall when monogamy put into polygamy situation they were far less likely to survive because of the lack of harassment they usually experience)

differences in optimal mating rate

due to differences in investment requirements for gametes and offspring, males typically have higher optimal mating rate compared to females (females benefit from having more reproductive options declines due to having to care for the kids lol)

harassment

persistent mating attempts despite clear sexual rejection, can directly reduce fitness via physical injury or wasting time and energy that could be spent on actual reproduction… attractive females receive more harm from males, genetic variation in male- induced harm, females who mater with high harm males prefer low harm due to shit experience

differences in amount of competition for access to mates

due to differences in optimal mating rate, males typically engage in more competition for access to mates, so have evolved traits that help them win

when does sexual conflict take place

before and after mating, same for sexual selection

accessory gland proteins

benefits for males: increased sperm competition success, decreased mating receptivity of mate, increased short- term reproductive potential of mate

benefits for females: increased short- term reproductive potential

cost for females: decreased lifetime reproductive potential, decreased lifespan

when makes perceive high degree of sperm competition…

invest more into ejaculate traits, which makes these males more harmful to females (Shortens lifespan)

intralocus sexual conflict

within genes, when the fitness optimum of a trait controlled by the same gene differs between the sexes (so like a single gene that controls body size but selection favors larger body size in males but small in females)

evidence of intralocus conflict

as larva positive fitness correlation between males and females of the same genotype but negative as adults

interlocus sexual conflict

between genes, when the fitness optimum of a trait is controlled by different genes differs between sexes (optimal mating rate, parental behavior)

are all males using exploitative strategies

traditionally thought more socially dominant males are more harmful towards females, but new evidence suggests that socially subordinate males use exploitative traits more due to lack of experience (makes them kinda aggressive)

why fight

most aggressive conflicts due to competition: obtaining resources, defend against attack, conflict over mates, establish status and social hierarchies, deter rivals from future conflict (can be strategic)

why are males more aggressive (proximate and ultimate explanation)

proximate: more competition during development, more testosterone

ultimate: increased reproductive success, less investment into reproduction, can afford to invest in other strategies, males need to compete more

sex differences in aggression

men more likely to be aggressive, more likely to be the target of aggression, trait differences like body size. peak aggression for both sexes is late 30s

body differences

men are just bigger and stronger and show much more interest in sports that involved physical combat

same sex homicides

men kill other men at a far greater rate than women kill other women

bullying in schools

sample of high school, more boys report to being physically hurt during bullying whereas girls had more verbal abuse

what causes variation in male aggression: young male syndrome

young male syndrome: most prone group to engage in risky forms of aggression because the have the most to gain from it (reproductive success)

what causes variation in male aggression: endocrine stuff

higher levels of testosterone

what causes variation in male aggression: marital and ~~employment~~ status

unmarried and unemployed men more likely to be the offenders and victims of violence

what causes variation in male aggression: social status and reputation

socially dominant males tend to be more aggressive

what causes variation in male aggression: sexual jealousy and intrasexual rivalry

males more likely to use aggression when infidelity is involved

what about females?

not typically physically aggressive, more relationally aggressive, tend to derogate the appearance and reputation of competitors

women perceive physical traits to be more threatening

face (femininity), breast size, waist to hit ratio

direct vs indirect

females more likely to use indirect tactics of aggression (gossip, insults, rumours), males more direct like physical

warfare

almost exclusively pursued by men, intended victims are usually men, and its cost vs benefits

conditions for warfare adaptations

1. long term gain in reproductive resources outweighs survival costs (go home to girls lol)
2. members must believe coalition will be victorious… individuals should anticipate that they will win and get resources
3. individual risk has to translate into corresponding share of benefits (Anticipate the risk is worth reward, sensitive to cheaters)
4. veil of ignorance about who will live or die (perceive risk of mortality as being random)

what specific adaptations would we predict exist to psychologically succeed in warfare?

1. men but not women have adaptations for coalitional warfare
2. access to mating will be primary benefit, with resources as another potential benefit
3. men should have adaptations to defect when death appears imminent
4. men should be more likely to go to war when odds of success are high
5. men should have adaptations to detect and punish cheaters and defectors
6. men should have adaptations to detect, prefer and enlist good men (Who wont cheat)

women engaging in war

most armies composed of men, queens in europe were much more likey to wage war than kinds

men more likely to spontaneously assess their fighting ability

like that is just too funny… daily?????? bffr

psychological factors that may facilitate success in war

men tend to have strong fear of acting cowardly, and derive great excitement, glory and brotherhood at the prospect of war

quality preference in coalitional allies

coalition: group of people whom you work with to pursue common goals

compared to women, men prefer all physical/ strength related qualities in ally

homicide

80% of homicides committed by men out of 17000 in usa, sex differences explained by culture specific gender norms

adaptive benefits of committing murder?

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protecting of self/ kin, gaining access to limited resources, eliminating rivals, depriving rivals of access to valuable stuff

men report higher likelihood of committing murder if there is no consequence

no way to get caught, men much more willing to say they would kill, additionally unmarried and unemployed even more likely

income and homicide rates

no relation, other than extremely rich being really low every other bracket pretty equal HOWEVER areas with higher income inequality have higher homicide rates

evolutionary psych and burden of proof

draws evidence from everywhere, need a lot and of high quality

when does experimentation come into evo psych

traditionally theory driven approach, tooby and cosmides methods of studying!!!!!!!!!!

tooby and cosmides methods GO BACK TO LECTURE 16 AND MAKE A DOCUMENT

1\.Use evolutionary theory as a starting-point to develop models of adaptive problems the human psyche had to solve

2\.Attempt to determine how these adaptive problems manifested themselves in Pleistocene conditions, and endeavour to establish the selection pressures.

3\. Catalogue the specific information processing problems that must be solved if the adaptive function is to be accomplished. Develop a theory

4\.Use the theory to determine the design features that any cognitive program capable of solving the problem must have

5\.Eliminate alternate candidate models with experiments and field observation.

6\.Compare the model against the patterns of manifest behaviour that are produced by modern conditions.

contemporary theories of altruism

nepotism, reciprocity, costly signaling theory

contemporary theories of altruism: nepotism

altruism can be selected for it is kin- based

contemporary theories of altruism: reciprocity

altrusim can be selected for if it is repaid by the beneficiary

contemporary theories of altruism: costly signaling theory

altruism can be selected for if it acts as a display that has some benefit, in the context of sex or prestige

generosity toward non kin

humans are generous, more so than most or all other species. ancestral examples: food sharing and alliances

modern examples: giving blood and generations

prisoners dilemma

if played once, dominant strategy is always defect. dilemma highlights the potential outcomes of reciprocal altruism because b>c if both cooperate, but c>b if partner defects

cooperate or not cooperate

defection pays better than cooperation, mutual cooperation is better than mutual defection… decision rule: cooperate only with those who tend to cooperate but requires repeated interaction and the ability to discriminate against defectors

best strategy to win prisoner’s dilemma?

tit for tat, cooperate first round, then reciprocate every move after

In general, successful strategies:


1. Tended to not be the first to defect
2. Only retaliate after the other has defected
3. Be forgiving

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good reason to hypothesize behaviours could naturally evolve

what factor’s influence one’s willingness to cooperate

scale of competition: as becomes more local, less likely to emerge

social contract theory: humans have evolved certain abilities to detect cheaters and engage in successful social exchange

individuals cooperate more when the scale of competition is larger

global comp: subjects who received the most points in the class won a prize

local comp: top scorer in each group of 3 won a prize

social contract theory (5 adaptations)

1. The ability to recognize many different individual humans
2. The ability to remember the histories of interactions with different individuals
3. The ability to communicate one’s values to others
4. The ability to model the values of others
5. The ability to represent costs and benefits, independent of the particular items exchanged

do people remember cheaters

humans better at wasson selection task when social contracts are involved, humans also show enhanced recognition for cheaters when cheating behaviour is rare (among a crowd)

friendship

look for people who emit positive qualities, are good at knowing what you want, are considered irreplaceable

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friends tend to exhibit more genetic similarity

cooperative coalitions

likely evolved for hunting, raiding, defending, etc

problems of defection and free riding… punishment as enforcement?

individuals who display cowardly traits not trusted in groups

gazella stotting

stotting signals individual vigor to deter the predator, making them less likely to be caught by prey… this kinda fakes dominance and takes a chance!

required conditions fro costly signaling

* signal must be of interest to observer and provide relevent info about signaler
* potential benefit must outweigh cost
* cost of signal must be high to ensure the honesty of it

having an audience is important for signaling

eyes over the coffee donations, if watched more likely to donate… switched poster between eyes and flowers, more donations with eyes directly forward

generosity as a costly signal

resources, abilities, willingness to cooperate, multiple beneficial qualities, mate value

signalling resources

means of validating status, bill gates has given over 1 billion to charity, but we KNOW he did this… pressure of society, literally indian weddings

signaling abilities

Meriam island turtle hunters

Hunters: leader, jumpers, harpooner, driver

Jumping signals: agility, strength, courage

Leading signals: leadership, knowledge, generosity

Hunting is an effective signal: people know who hunters are

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turtle hunters more likely to have offspring than age matched males

signaling cooperative intent

public goods game, players contribute to public fund but this is only beneficial if everyone contributes… players who contribute most in the first game were entrusted with more “money” in second game, being altruistic has future benefit

signaling attractive qualities

bravery, risk taking, individuals give more if potential partners are watching. amount donated depended on if the partner was random or chosen and whether they were watching you play

altruism and attractiveness

altruists like helping, vs non altruists, altruism increases attractiveness especially for men unless just tryna hook up

how developmental psych supports evo psych

1\.Replicating evolutionary psychology research with adults in infants

2\.Investigating developmental consistencies

3\.Investigating differences in development due to environmental input

replication with infants

results in adults that may suggest evo derived behavior, infants help enhance through replication. if show same result with infants suggest deep rooted in our psych but this not required

animates vs inanimates

living lions vs non living mug, attentional bias as evidence of an evo derived. flicking between images until participants find difference, way more likely to find with animate… findings were unlikely to be due to learning or cultural input so against what was expected

investigating developmental consistencies

we do not expect everything we see in adults to exist in infants, critical periods are developmental data that supports evo psych

critical/ sensitive period

points in development where very specific learning can take place, consistent across all humans given enviro inputs so strong evo based theories

language critical period

critical period for language ends around puberty, neuroimaging supports that the age of acquisition matters → later learned requires more brain function in both hemispheres (language typically processed in left, but requires use of the right)

what is the evo explanation for this critical period

signifies that during the timepoint when acquiring a given skill is most adaptative, modern theories think it was essential to learn to communicate with others early in life but no real need for second lang which is why we “lose” ability post puberty

differences in development

not everything is consistent, but differences in development appear to be due to consistent differences in the enviro

life history in developmental context

optimally strategize for different enviros

nature vs nurture

naturists like plato believe born knowing everything, empiricists like Aristotle believe humans are born a blank slate and can learn everything

piagetian developmental psych

stage- like theory of development and constructivist view= children construct their own meaning of their experiences. stages are not truly reflective of real development and often underestimated kids plus too limited on how children learn

associationism

argues that people have general purpose learning mechanisms that are usually based on stimulus association, like operant and classical conditioning, also problematic because this is not the only way of learning

evo psych as an approach

based on using the concepts of evo and adaptations to guide empirical work, because evo theory is so broadly applicable this fits with broad nature of development

modular views of psych

argues that our cognitive architecture is arranged into domain- specific modules that deal with specific learning or developmental problems

modular views of psych: math

children can differentiate between small groups of numbers precisely but struggle with larger groups more than 4/5, kids show various other discrepancies beyond counting when it comes to large vs small numbers, suggesting evidence of two separate number systems learned via own mechanisms

modular views of psych: categories

distinct categorization strategies with kids because attribute different rules based on whether natural or not: table vs tiger, tiger still tiger is not orange but table not table if no surface, attribute internal sources for animate but not inanimate

perceptual narrowing

ex value of acquiring second language is lower than acquiring first language, in many cognitive domains it makes sense to have more specific skills than general skills (like how certain phenomes can’t be heard) so they become more specialized for our actual life

other race effect

harder to differentiate faces of races other than own, however children do not have this same effect until school age because do not suffer from same social biases as they have not been culturally learned