Evolutionary explanations of human aggression

Evolutionary explanations of human aggression

1. Jealousy

   • Cuckoldry: the reproductive cost that might be inflicted on a man as a result of his partner's infidelity.
   • Sexual jealousy has an adaptive function as it deters a mate from sexual infidelity, minimising the risk of cuckoldry.
     • Mate Retention Strategies: 1) direct guarding - restricting their partner's independence and 2) negative inducements - violence or threats of violence.
   • Daly et al (1982) - male sexual jealousy is the single most common motivation for killings in domestic disputes in the U.S..
   • Shackleford et al (2005) - found in a questionnaire that men use two broad types of retention techniques: inter-sexual negative inducements and direct guarding, alongside emotional manipulation. Women whi experienced this were also more likely to experience violence from their partner.
     • WEAKNESS: social desirability bias
     • STRENGTH: research support - Buss and Shackleford (1997) found that men who suspected that their wives might be unfaithful in the next year exacted greater punishment for known or suspected infidelity.
     • STRENGTH: practical applications - the research can be used to indicate warning signs of violent or abusive relationships
     • WEAKNESS: gender bias/ gender differences - Takahashi (2006) found that the neural response to imagined scenes depicting sexual infidelity and emotional jealousy was different for men and women. Men showed greater activation of the amygdala and hypothalamus.

2. Infidelity

   • Daly et al (1982) - the detection or suspicion of infidelity is a key predictor of partner violence.
   • Violence towards a pregnant partner may follow infidelity. When a woman becomes pregnant with another man's child, the unction of violence towards her may be to terminate the pregnancy , thus eliminating the potential offspring of a rival and leaving her to bear offspring with him.
   • STRENGTH: Research support - Burch and Gallup (2004) found that the frequency of violent acts towards pregnant partners was roughly double that directed towards partners who were not pregnant, with sexual jealousy characterising those men who committed violence against their pregnant partners.
   • STRENGTH: Research support - Taillieu and Brownridge (2010) found that women abused while pregnant were more likely to be carrying the child of a man other than her current partner.
   • WEAKNESS: Gender bias - most studies of infidelity have focused on men's mate retention strategies, and men's violence against women. Women may also engage in mate retention tactics and can be violent towards their partners.
   • WEAKNESS: evolutionary explanation - can't explain why people react in different ways when faced with the same adaptive problem. Buss and Shackleford suggest that it can't account for why different males respond in different ways ti a their partners infidelity (i.e. getting drunk, aggressive mate retention strategies or murder.).