Conflict

Conflict

1. parental investment

   • Trivers - any investment by the parent in an individual offspring that increases the offsprings chance of surviving at the cost of the parent's ability to invest in other offspring
   • 3 fundamental trade offs - energy devoid to parenting cannot be used for other functions - how much to invest in current as opposed to future offspring - quantity vs quality
     • who should invest in the offspring? typically its the female
       • parental investment r/k theory - R = growth rate of population over time - K = carrying capacity - trade off between quality and quantity of offspring
         • k strategy - having a slow growth population with more investment
           • r strategy - loads of offspring, less investment
             • Humans - more like K strategists - parental investment in humans - expensive - but kids might be useful e.g in farming families
               • People leave more in wills for kin with higher r (kids etc)
                 • parental biases - adjust level of investment - goal is to produce grandkids - grandparental investment - Caregiven in order = maternal grandmother, maternal grandfather, paternal grandmother, paternal grandfather
                   • options are an exception to kin based investment - cuteness - neoteny (juvenalisation) - delayed development - look cute to elicit parental affection - cuteness can be adaptive by acting as a proximate mechanism for extracting care - it can also be exploited

2. Conflict

   • in spite of occasional outbreaks of harmony, families are shaped by conflict - parent offspring conflict - in utero conflict. spontaneous abortion - embryo must honestly signal quality by releasing a hormone - competition for blood - pregnancy sickness - prevent ingestion of teratogens and abortifacents
     • post natal conflict - notably weaning conflict - offspring quality conflict - abandon of kill infants with deformities "ill omens" cannot look after them in poorer countries, get abandoned frequently
       • parental resources - burden of twins - widowhood - young, single women and abortion
         • cinderella effect - stepparents more likely to abuse and kill 'their' kids than bio parents - consistent with parental investment theory
           • paternity uncertainty - infant appearance - anonymity or look like dad?
             • Infanciticide - paternity uncertainty can cause dads to kill child - can be adaptive - scheduling investment - kill the kids until you're ready to have them - culturally universal (apart from in Africa) - causes: paternity uncertainty, selecitve infanticide
               • selective infanticide - kill least valuable sex - fisher's sex ratio - trivers'willard hypothesis - invest more in males when in good conditions and more in females when in poor condition - males more energetically difficult to produce because of food etc - invest most in more valuable sex
                 • Honour killings - typically sisters and daughters - chastity guarding - reproductive control by parents - sibling rivalry - siblicide - surplus offspring - rvs k strategies brothers killing brothers, typically over access to females or resources
                   • sexual jealousy - 60% of male undergrads found idea of partners infidelity distressing - 83% women found emotional infidelity distressing vs 40% of men - physiological evidence
                     • males more likely to regard mates as property - sexual coercion e.g mate guarding, threatening rivals

3. Non-kin conflict

   • competition results in conflict - conflict often resolved by aggression - conflict can be strategic - whether to be a hawk (fight) or a dove (retreat) depends on what the other does - conditional strategy
     • kinds of competition - scramble - everyone goes for it - e.g sheep getting grass - contest - actual direct conflict - spiteful - compete for sake of winning

4. aggression

   • daly and Wilson - homicide - seminal use of evolutionary psychology - looked at homicide records to understand who kills and why - is it adaptive
     • Co-opt resources - taking resources from someone else
       • defence - defend your own resources
         • intra sexual competition - male to male for access to females
           • dominance and status
             • deterrence of aggression - Cold War
               • punishment - maintain cooperation and deterrent
                 • inter-sexual coercion - males coerce females - males benefit more from polygeny - results in sexual selection - rape has been proposed as conditional mating strategy
                   • sex differences - women less physically violent - women more likely to kill men out of self defence - 80% of homicides committed by men - men killing women - byproduct of sexual jealousy - killing women is byproduct of sexual aggression (slip up hypothesis)
                     • men killing men - young men especially - reputation and risk taking - intra sexual competition - is there a homocidie module?

5. Is aggression learned?

   • Bobo doll experiment
     • evidence for video games and tv leading to violence are sketchy at best - cultural differences in aggression - men in southern states more aggressive than northern states - evolutionary origins - rates of lethal violence in chimps are comparable to human hunter gatherers - Rousseau's myth - a society without violence - no non-violent societies - welfare is cultural universal - best predictor of warfare is a high proportion of young men in a population - parochialism (in group favouritism) xenophobia (out group)