Evolutionary explanations of human aggression

• Evolutionary explanations of sexual jealousy:

  • Sexual jealousy is a major motivator of aggressive behaviour in males which can be given an evolutionary explanation
  • Unlike women, men can never be totally sure about whether a child is biologically theirs or not
  • Therefore, men face the threat of cuckoldry (having to raise offspring that is not their own) 
• Evolutionary explanations of sexual jealousy:

  • Men in our evolutionary past who were able to avoid cuckoldry were more reproductively successful as they were able to pass on their genes
  • So psychological mechanisms, such as sexual jealousy, have evolved in males to decrease the chance of cuckoldry
  • This sexual jealousy can lead to aggression 
• Mate retention strategies :

  Wilson and Daly (1996) identify two major mate retention strategies involving aggression:

  • Direct guarding: a man’s vigilance over a partner’s behaviour (e.g. checking who they’ve been seeing)
  • Negative inducements: Issuing threats of consequences for infidelity (e.g. ‘if you leave I’ll….)
  • Such behaviours are linked to violence
  • Wilson et al. (1995) found that 73% of women who reported that their partners used mate retention strategies also suffered violence from their partners
• Mate retention strategies and violence:

  • Shackleford et al. (2005) studied men and women in 107 married couples and asked them to complete questionnaires assessing men’s mate retention behaviours and women’s experience of violence from their partners.
  • They found that there was a strong positive correlation between men’s reports of their mate retention behaviours and women’s reports of their partners’ physical violence
  • This shows that men who used guarding and negative inducements were also more likely to use physical violence against their partners
• Evolutionary Explanation of Bullying in Males

  • Bullying occurs because of a power imbalance: a more powerful individual uses aggression deliberately and repeatedly against a weaker person
  • Our evolutionary ancestors may have used bullying as an adaptive strategy to increase their chances of survival by promoting their own health and creating opportunities for reproduction
  • In men, bullying suggests dominance, acquisition of resources, strength and also wards off potential rivals (Volks et al., 2012)
• Evolutionary Explanation of Bullying in Males

  • These characteristics associated with bullying deliver the ideal combination of access to more females and minimal threat from competing males
  • Therefore, aggressive bullying has been naturally selected because these males would have reproductive success
• Evolutionary Explanation of Bullying in Females:

  • Female bullying often takes place within a relationship and is a method of controlling a partner
  • Women use bullying behaviour to secure their partner’s fidelity, which means they continue to provide resources for future offspring
  • Again such behaviour would be naturally selected because it enhances the woman’s reproductive success
• AO3:

  • One strength of evolutionary explanations of human aggression is that there is research to support the link between mate retention strategies, sexual jealousy and aggression
  • Shackleford et al.’s (2005) study is an example of this as it shows that direct guarding and negative inducements are overwhelmingly used by males, against both other males and females
  • This suggests that the risk of cuckoldry is linked to aggression, which supports the explanation about the adaptive value of aggression
• AO3:

  • strength of the evolutionary explanation of aggression is that it explains gender differences
  • Males engage more often than females in aggressive acts, especially physical aggression
  • Campbell (1999) argues that aggression in females risks the survival of their offspring so a more adaptive strategy is to use verbal aggression to keep a partner who provides resources
  • The fact that the evolutionary explanation can explain such gender differences in aggression increases the validity of this kind of approach
• AO3:

  • strength of the evolutionary explanation of aggression is its real life applications
  • Rigby (2010) reviewed several established anti-bullying interventions
  • Most interventions fail to recognise that bullies bully because they gain advantages. It would make no sense for a bully to voluntarily give up the power they have over other without some form of compensation
  • An evolutionary understanding of bullying as an adaptive behaviour can help us devise effective anti-bullying interventions to increase the costs of bullying and the rewards of pro-social behaviour
• AO3:

  • limitation of the evolutionary explanations of aggression is the issue of cultural differences in aggression
  • The evolutionary explanation predicts aggression is present in all cultures because it is used everywhere to increase survival chances through greater reproductive success
  • However, the Kung Sang people of the Kalahari discourage aggression and those who use it lose status and reputation
  • The fact that the Kung Sang do not use aggression, whereas other cultures do, suggests that aggression is not universal. This contradicts the evolutionary explanation of aggression
• AO3:

  • limitation of the evolutionary explanation of aggression is that much of the research is correlational
  • As it is extremely difficult to test whether certain behaviours have evolved to benefit survival, much of the research has to be correlational
  • For example, research exploring the correlation between mate retention behaviours and aggression
  • This makes it very difficult to establish precisely how valid an evolutionary explanation of aggression is as we cannot determine cause and effect