Buss, Chapter 10 Aggression and Warfare

1
Buss, Chapter 10Aggression and Warfare
2
Adaptive gains from aggression

• Gain others resourceson individual group
  level (bullies, coalitions)
• Defend against attackbest defense is a good
  offense
• Inflict costs on rivalsincreases own relative
  position

3
Adaptive gains from aggression

• Gain in status hierarchywill depend on whether
  own group would consider aggression as earning
  status vs. losing it
• Cultivate fearsome reputation to deter rivals
• Deters mate from sexual infidelitydata from
  womens shelters supports idea

4
Context specificity of aggression

• Aggression not unitary urge, but
  context-specific, with contexts triggering
  aggression being predictable by evolutionary
  adaptive considerations
• That is if aggression solved adaptive problems
  for ancestors in certain situations, then those
  situations more likely to trigger aggressive
  behavior in us

5
Context specificity

• Example spouse batteringmore likely with
  higher mate value female (e.g., young, good
  looking) paired with lower mate value male (low
  income, not good looking, lost job) because odds
  higher female may leave, male more aggressive in
  trying to deter infidelity

6
Context specificity

• Example likelihood of retaliationbullies more
  likely to pick on the weak (whipping boys) than
  on those able and likely to retaliate males less
  likely to abuse mates if she has brothers
  father living nearby
• Thus, aggression not just some urge all people,
  especially males, have, but is a tendency evoked
  only in situations where it served an
  evolutionarily adaptive purpose

7
Gender differences in aggression

• Historically, cross-culturally men more
  aggressive than women, and men usually are
  victims true in many other species
• Primary resource they fight for access to women
• Degree of risk taking to gain access depends on
  variance among haves (those who have sexual
  access) and have-nots (those who dont)

8
Gender differences

• In species with high degree of polygyny (many
  females for some males, implies none for other
  males), fierce competition and sometimes
  desperate strategies by have-nots
• Those unwilling to take risks for sexual access
  are selected against (no mating, no offspring!)

9
Gender differences

• Women also aggressive with other women usually
  more verbal and less intense comments most
  likely about traits men value (about other
  females looks, age, infidelity)
• Reason for lower intensity womens own lives
  more valuable than mens, as they need to provide
  the parental care for offspring makes less sense
  to take risks

10
Empirical evidence

• Homicide MgtF as perpetrators cross-culturally,
  metanalyses
• Bullying in school MgtF, especially for violent
  aggression FgtM only for name-calling spreading
  rumors about other females (note names rumors
  predictable by mate-competition theory)

11
Empirical evidence

• Australian AboriginesMgtF in violent aggression
  WgtM in verbal aggression (and in using sticks for
  aggression)
• Male aggression often due to mate competition
  young male syndrome
• Males directly attack rivals aggress against
  mate due to sexual suspicion or jealousy need to
  establish status through fighting, bravery

12
Contexts triggering aggression in men

• Marital employment status no woman, no job
  high rate of aggression
• Status linked to mating chances males fight to
  gain or avoid losing status (note bar fights
  about such status)
• Competition over womenaggression mate
  guarding forming war parties to raid other
  groups and gain access to women

13
Womens aggression against other women

• More verbal less physical
• Verbal derogation focuses on other womans
  physical appearance, promiscuity logical to
  focus on things valued by males
• Context-specificity woman will mention others
  promiscuity only if male looking for long-term
  mate!
• Female-female aggression often sexual rivalries

14
Women aggressing against men

• Defending self against his attack
• After history of abuse by male

15
Warfare

• Always male groups, throughout history
• What are benefits that can outweigh obvious
  costs? Conditions needed for war to occur
• Access to females (status within group gain
  females from other group)
• Belief will win
• Must be commensurate reward for risk, on
  individual basis

16
Warfare

• Must not know in advance who will live die

17
Warfare

• Evidence for men having more adaptations for war
  than women
• Historical statistics
• Spontaneously assessing fighting ability (e.g.,
  study of frequency of thinking about relative
  ability)
• Males strength, navigation skills, forming
  same-sex coalitions

18
Warfare

• Evidence that males do get more access to women
  by fightingstudies of gangs

19
Evolved homicide mechanism?

• Study of thoughts of committing homicide MgtF in
  number of such fantasies
• Two main theories slip-up hypothesisinstrumen
  tal aggression that got carried away evolved
  homicidal mechanism (Buss)certain situations can
  trigger homicide, and these situations make some
  sense from EP perspective

20
(No Transcript)