1 / 23

War and Peace

War and Peace. Aggression in an Evolutionary Context. Aggression (1). May be defined as “behavior that is intended to injure another person who does not want to be injured” (Brehm et al., 1999) May be Instrumental Harm inflicted as a means to an end Emotional

halima
Download Presentation

War and Peace

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. War and Peace Aggression in an Evolutionary Context

  2. Aggression (1) • May be defined as “behavior that is intended to injure another person who does not want to be injured” (Brehm et al., 1999) • May be • Instrumental • Harm inflicted as a means to an end • Emotional • Harm is inflicted for its own sake

  3. Aggression (2) • Benefits • Co-opting others’ resources • Defense against attack • Intrasexual competition • Status hierarchies • Deter rivals • Deter sexual infidelity in mates

  4. Aggression (3) • Context-specificity • Spousal violence due to jealousy • Reputation and escalating retaliation • Ability to retaliate • Size, strength, skill • Proximity of kin

  5. Instinct Theory: Freud • Two specific instincts: Life (Eros) and Death (Thanatos) • Death instinct was a post WWI concept, representing an unconscious desire to escape life through death • Aggression is caused by a conflict between Life and Death instincts, targeted towards others

  6. Instinct Theory: Lorenz • In 1966, the ethologist Konrad Lorenz published On Aggression • Argued that aggression is adaptive • Successful aggression leads to securing of • Food • Territory • Mates

  7. Instinct Theories: Problems • Tautological, untestable hypotheses • Due to their inflexibility, they do not effectively account for environmental influences that lead to cultural variation • Commit the nominal fallacy • Assume an effect has been explained simply by naming it • The problems with instinct theory, however, do not refute the influence of evolution

  8. Sex Differences in Aggression (1) • Once again, we return to minimum investment • Men have greater reproductive variance, which is constrained by access to mates • Thus, men are in direct competition with each other for mates • The greater the variance (e.g., effective polygyny), the greater the sexual dimorphism

  9. Sex Differences in Aggression (2) • Overwhelmingly greater number of • Murders perpetrated by males • Male homicide victims • Females do, however, also engage in aggressive acts • Verbal aggression is common • Simple assault • Serious harm is very rare, though

  10. Sex Differences in Aggression (3) Campbell (1995)

  11. Young Male Syndrome • Young men have the greatest degree of intrasexual competition for mates • Thus, they employ riskier strategies • Hunting • Combat • Defense • Through reputation, these behaviours serve to impress females and deter rivals

  12. Young Female Syndrome? • Campbell argues that the overall relationship between age and violence holds for females as well • Teen girls and competition for mates • Biased sex ratio with fewer males • Proportion of resource-rich males

  13. Context Effects of Aggression (1) • Male-Male • Marital and employment status • Status and reputation • Sexual jealousy and intrasexual rivalry • Female-Female • Intrasexual rivalry

  14. Context Effects of Aggression (2) • Male-Female • Sexual jealousy • Female-Male • Defense against attack • Other effects • Variation in testosterone (T) • Heat effects • Hypoglycemia (e.g., in Qolla)

  15. Circannual Rhythms of T 2 (1) = 10.007, p = .002 Krupp et al. (2002)

  16. Heat Effects 2 (3) = 34.44, p < .001 Krupp et al. (2002)

  17. Warfare (1) • Extremely sexually-dimorphic behaviour • Benefits • Increased sexual access • Increased resources • Improved reputations • Costs • Death or injury • Lowered reputation

  18. Warfare (2) • Unique aspect of warfare is its cooperative nature • Conditions for its evolution • Average long-term gain in reproductive resources must outweigh costs • Members must believe that success is likely • Risk and contribution of each member must be related to benefits • Veil of ignorance over likelihood of survival

  19. Evolutionary Predictions (1) • Males will have adaptations for warfare • Historically, only males seek war • Sexual access will be primary benefit • For gangs and Yanomamö, this is true • Adaptations for defecting might also have evolved when likelihood of death was high

  20. Evolutionary Predictions (2) • Warfare should be more likely when chances of winning are high (e.g., number of soldiers) • WWII and coalitional size • Adaptations to enforce “risk contract” • Reputation • Males will have adaptations to prefer more able, willing men as coalitional members

  21. Group Processes • It is extraordinarily easy to stimulate intergroup competition (Us vs. Them) • Robber’s Cave experiments • 11 year old boys formed two groups • Escalated competition rapidly over one week • Were only able to deescalate once experimenters gave them a task that they could only perform together

  22. The Wrap-Up • Benefits to aggressive behaviour • Instinct Theories • Sex Differences • Young male & young female syndromes • Context effects • Evolutionary perspectives on warfare

  23. Things to Come • Sexual conflict • Occurrence and timing of sex • Jealousy • Mate retention tactics • Access to resources • Rape

More Related