Social behaviour & conflict Flashcards
J.B.S. Haldane said he’d famously risk his life for the sake of 2 (not merely 1) brother. Why is this significant
(ideally would save 8)
From a fitness perspective this is adaptive because there is a greater gain for the continuation of the family line (indirect fitness)
W.D termed inclusive fitness (total fitness of an individual) includes which 2 types of fitness/explain them
direct fitness- personal reproduction (your own kids)
indirect fitness- reproduction
Outline Hamilton’s rule, what each part of the equation means?
an act has a costs for the actor (donor) and benefits for the recipients
C < R x B
C- Cost to actor (must be less to the donor)
R- Coefficient of relatedness (degree to which two ppl are related)
B= benefit to recipient
(C & B incorporate genetic relatedness between donor and recipient (r)
How is relatedness calculated?
What relatedness of child/g parents, sisters/brothers
Via path analysis in which you trace degree of relation between actor and recipinet, with 1/2 of each parent’s genes passed on to offspring.
Probability of sharing gene is product of the independent probabilities and the sum of the separate paths
child-gp r = 0.25
sis/brothers = r = 0.50
What does Trivers (1972) parental investment theory entail?
Invest in kids up to a point (trade-offs occur).
Parent’s investment in offspring that increases their child’s chance of survival at the cost of parent’s ability to invest in other offspring
What are the 3 fundamental trade-offs in Trivers’ parental investment theory
1) Energy devoted to parenting cannot be used for other functions (e.g. mating, maintenance)
2) level of investment to put into current and future offspring
3) Quantity vs quality
Imagine the logistical growth curve of populations, how would it look?
An s-shaped curved, where it levels off at the top is the ‘caring capacity’.
exponential initial growth then levels out
Difference between an r-strategy and k-strategy?
R- large families
K- small families (more common today, since investment in kids is far more costly)
Study on investment in kin in wills- main findings? which is surprising from an evo persp?
People leave more in will for kin with a higher r - those more closely related to them.
Spouse (non-related)- they can look after you’re kid
How does investment from grandparents look
They decrease in their care/investment in young in this order:
maternal g mother, maternal g father, paternal g moth, paternal g fath
Adoption
Exception to kin-based investment, behaviour seen in various animals- a special attraction to young and vulnerable
What’s adaptive about being cute?
An extended juvenile period draws attraction - acts as a proximate and draws care from elders
looking cute can be exploited ie. cuckoos exploit cues of cuteness
What is in utero conflict?
between child-mother there is:
competition for blood, averse to certain smells, hormones, pregnancy sickness (embryo wants to protect itself from averse substances) i.e. teratogens effect i.e. phalidomide effects
Further parent-offspring conflict upon birth, quality of child?
Post natal conflict- weaning off from the child
abandonment/killing of child with deformities, evolutionary adaptation to rather have stronger/healthier offspring
Effect of parental resources on keeping a kid?
Burden of twin (more resource intensity), widowhood, single/young woman, abortion
What’s the cinderella effect?
step-parents invest less into their step-children. crime records show more abuse of step-kids
Conflict arising from paternity uncertainty?
Infant appearance- look like the dad = deffo you’re kid, proves relatedness. If you want your dad to look after you, best if you actually look like him
Infanticide in animals/humans
Infanticide adaptive strategy for male animals, kill young that arent theres
In humanws-
scheduling investment (have kid at right time), culturally universal (except in africa)
What’s selective infanticide? Trivers Willard hypothesis
Investing in the more valuable sex (males)
males- invest in them more when in good condition,
females- invest in them more when in poor condition
Fisher’s sex ratio and sexy son hypothesis (1930)
it’s more adaptive to have male offspring, can reproduce and pass on genes more than females can
Chastity
Females kept under guard until ready to birth- male domination
Non-kin conflict, game theory
Competition results in conflict and resolving occurs through aggression.
Game theory explains this, choosing to fight or retreat dependent on what the other animal involved does
Give the types of competition
scramble- most common form, individuals compete for a resource that is spread out
contest- direct conflict over a defendable resource (often for male/female access)
spiteful competition- compete for a resource you can’t even get anymore
What 2 theories are proposed for where aggression comes from
one theory says we are socialised, another suggests it has biological basis
Provide some adaptive value for aggression-
co-opt resources, defence, intra-sexual competition (mainly male-male), dominance/status, intersexual coercion- men historically rape women, detere aggression from others
Why is there sexual aggression?
Because males benefit from polygyny and females monogamoy = jealousy along the line will occur
Sex differences in aggression
Women are less physically violent compared to men, women more likely to kill only out of self-defence
What’s slip up hypothesis (aggression) ?
Idea that killing is a by product of men’s aggression (and so the act itself isnt always meant for killing sake)
Killing women by men as by product of sexual jealousy.
Young females more likely to be abused and killed (since more of a valuable resource
What did Buss (2005) propose there could be
a homicide module in the brain - suggest there could be context-sensitive tendency to kill
What does Albert Bandura think the origin of aggression is?
Believes it is learnt- social learning theory proposes we are socialised into aggressive behavioural tendencies i.e. bobo doll study findings
What did Cohen & Nisbitt find in their study on conflict and culture?
In the insult condition, northern state p’s had far lower testosterone levels than their southern counterparts
What do evolutionary histories (homologies) show regarding aggression?
Rates of violence in chimps comparable to human huntergatherers.
Homicides- humans kill each other as much as chimps.
non-lethal aggression 2-3 times higher in chimps
Homologies of aggression are contrary to Rousseau’s theory- what is it?
he believe you can have a society without violence.
state of ‘natural man’ living in harmony with the world
Bonobos the ‘hippies’ of the primate world- how do they best mate- theory name?
Not as aggressive as chimps.
They will preferentially mate with a male/female of similar aggression (self-domestication theory
Warfare a cultural universal - seen in animal world?
Chimps display war like behaviour- they will monopolise and occoput other groups territory, kill
Best predictor of warfare?
High proportion of young males. Men physically fitter, better adapted for war (violence in general).
- needs lots of group cohesion
War a cooperative enterprise- are they better adapted?
Yes, groups engaging in war -like behaviour are better able to penetrate opposition and destruct rivals
What is parochialism, xenophobia?
Par- in group favouritism
xeno- out group hostility
