Evolutionary Explanations of Human Aggression

Daly and Wilson (88) suggest men have different strategies for deterring partners from adultery. All are fuelled by male sexual jealousy, an adaption evolved to deal with paternal uncertainty.

Cuckoldry and sexual jealousy

• man could never be certain that they are the fathers of their children
• man might unwittingly invest his resources in offspring that are not his own
• adaptive function- deter a met from sexual infidelity, minimising risk of cuckoldry

Mate retention and violence

• Buss (98)- man developed ways of keeping mate
• restricting partners' autonomy, violence, threats of violence
• Dobash and Dobash- women cite extreme jealousy on the part of their husbands or boyfriends as the key cause of the violence directed toward them

Sexual jealousy and extreme violence

• Daly et al (82)- Male sexual jealousy is the most common motivation for killings in domestic disputes
• Dell (84)- sexual jealousy accounted for 17% of all causes of murder in the UK
• studies of murders involving 'love triangles' found 92% were male-male killings

Infidelity

• Daly (82)- the detection or suspicion of infidelity is a key predictor of partner violence
• men are more likely to engage in extra-marital affairs than women
• 1 in 10 women admitted to being unfaithful to their husbands

Sexual coercion

• Camilleri (04)- sexual assault of a female by her male partner was directly linked with the perceived risk of her infidelity
• Shields and Hanneke (83)- found female victims of partner rape were more likely to have reported engaging in extra-marital sex than women who had not been raped by their partner

Violence toward pregnant partners

• sexual infidelity by a women may sometimes lead to pregnancy
• if the child is born the mate risks investing in the offspring of another male and consequently lowering his own reproductive success
• function of violence may be to terminate the pregnancy and eliminating potential offspring of a rival

Uxorocide (wife-killing)

• Shackelford (00)- some men are especially prone to using violence or the threat of violence
• Daly and Wilson (88)- death of the partner from physical violence may be an unintended outcome of an evolutionary adaption designed for control rather than death

Evaluation: Research support (jealousy)

• Shackelford- clear relationship between jealousy, mate retention strategies and violence towards women
• Buss and Shackelford- men who suspected their wives might be unfaithful again exacted greater punishment

Evaluation: Practical applications (jealousy)

• particular tactics of mate retention used by males can be an early indicator of violence against their female partner
• findings can be used to alert friends and family to danger signs
• help can be sought before violence happens

Evaluation: a physiological basis (jealousy)

• Takahashi (06)
• neural response to imagined scenes of sexual infidelity is different in men and women
• used brain imaging techniques
• men showed much greater activation in the amygdala and hypothalamus when presented with scenes depicting sexual infidelity in their mate

Evaluation: not the whole story (jealousy)

• Edlund and Sagarin (09)- our understanding of the relationship between sexual jealousy and aggression is limited
• research doesn't tell us whether the perceived locus of responsibility moderates the jealous response
• research doesn't tell us whether the degree of perceived infidelity is important

Evaluation: Research support (infidelity)

• the link between infidelity and partner violence is supported by the finding that the risk of a partner's infidelity predicts sexual coercion among males, but not among females (Camilleri,04)
• found men convicted of raping their partners were more likely to have experienced cuckoldry risks prior to their offence compared to men convicted of non-sexual partner abuse

Evaluations: Pregnancy violence (infidelity)

• supporting evidence for a man who suspects that his partner is pregnant with another man's child is likely to inflict violence upon her
• frequency of violent acts toward pregnant mates was roughly double that directed toward partners who were not pregnant
• women abused while pregnant were more likely to be carrying the child of a man other than her current mate
• blows directed at abdomen- aimed at foetus (Valladares, 05)

Evaluation: Limitations (Infidelity)

• an evolutionary perspective on violence cannot explain why people react in different ways when faced with the same adaptive problem
• Buss and Shackelford (97)- cannot account for why different males respond in different ways eg some get drunk, some murder