Evolutionary explanations of aggression

Evolutionary explanations of aggression

1. Wilson et al (1995)

2. Shackleford et al (1995)

3. Kaighobadi et al (2008)

   • Studied 165 males who were all in secure relationships. Participants asked to complete questionnaires measuring how often they accused their partners of infidelity, how often they used retention strategies such as turning up unexpected to check on their partner and how frequently they used acts of violence. They found that as the number of accusations increased so did the number of retention strategies and the frequency of violent acts.

4. Infidelity and jealousy

   • Supporting research
     • Daly and Wilson (1988)
       • They found that male-male aggressive rivalry occurred in almost all cultures which they suggested provides cross-cultural evidence for the evolutionary explanation.
   • Oversimplified
   • Deterministic
   • Male aggression
     • Infidelity can pose a threat both to an individual's reproductive success and sometimes their survival too. In order to reduce the jealousy caused by the threat of infidelity individuals may become aggressive towards members of the same/opposite sex. Aggression can be intra-sexual (against members of the same sex) or inter-sexual (against members of the opposite sex.) Regardless of how faithful they are, women can always be certain that the child is theirs however for men this is not true. This is why for men sexual infidelity is more worrying as they cannot usually be certain that they are investing in their own children (fear of cuckoldry). Threat of infidelity (cuckoldry) ---.> causes feelings of jealousy ---> aggression towards females in an attempt to reduce infidelity.
     • According to the evolutionary explanation the reason why males are aggressive are to other males is to reduce competition for mates and therefore increase their chances of reproductive success. Males can reproduce an almost infinite amount of sperm and seek to impregnate as many women as possible. They therefore may use aggressive behaviour to warn off other males and to attract potential partners by demonstrating that they are capable of protecting themselves and any potential offspring.
   • Female aggression
     • According to the evolutionary explanation women are more likely to be concerned with emotional infidelity as if they their partner forms and emotional relationship with another women then they are likely to stop investing time/resources into them and their offspring. This therefore risks their, and their offspring's, survival chances. Therefore the feelings of jealousy caused by the threat of infidelity are what may cause females to be aggressive towards males.
     • Rather than being physically aggressive females tend to be verbally aggressive to one another. They are more likely to criticise another women's appearance/comment on their promiscuities. According to the evolutionary explanation this aggression is caused by feelings of jealousy towards other women. The theory would predict that females behave in an aggressive manner in an attempt to reduce the competition for mates and, if they already have a partner, to deter their partner from being unfaithful. This aggressive behaviour should therefore increase they own reproductive success and their offspring's chances of survival.
   • Aggression due to jealousy must be: adaptive as it provided a fitness advantage in our ancestral past, increasing chances of survival/reproductive success.

5. Brunk

   • Sexual infidelity of women brings uncertainty of paternity and fear of cuckoldry (investing in another man's child.) Sexual infidelity ---> jealousy in males and females. This supports the evolutionary explanation of aggression as men want to prevent their partner from committing adultery and fear cuckoldry as it wouldn't be beneficial for a man to raise/nurture the genes of another man's child.