Discuss Evolutionary Explanations of Aggression including Infidelity and Jealousy (8 & 16 marks)

One evolutionary explanation claims that Jealousy causes aggression and a big cause of jealousy is cuckoldry. This is where a woman deceives her male partner into investing in offspring conceived with another male. Men have evolved mate-retention strategies driven by sexual jealousy to stop this from happening to them which often involve aggression.

Camilleri (2004) devised the cuckoldry risk hypothesis which says that men will be more willing to use sexually coercive tactics when there is a high risk of cuckoldry. This was backed up by Lalumiere (2005) who found that men carry out partner rape in order to decrease paternity uncertainty.

Buss and Shackelford (1997) conducted a study which supported the idea mate-retention strategies involving violence have evolved in men by looking into what mate-retention strategies occurred in married couples. Men reported a higher use of intrasexual threats than women who were more likely to use verbal possession signals. They also found that men with younger female partners used more mate-retention tactics including violence and threats. This shows that mate retention strategies are used to deter cuckoldry as men with younger female partners are most likely to use it and they are thought the most likely to commit cuckoldry.

Another supporting study was carried out into mate-retention strategies by Shackelford (2005) who used a survey method to ask males about how often they used mate-retention strategies and how often they used violent acts towards their partners. In support of the evolutionary explanations they found that a male’s use of mate-retention strategies and emotional manipulation correlated positively with their use of violence against their partners.

Shackelford’s study however had a huge metholodgical issue in the fact that his data found a correlational link. This therefore cannot show a causal relationship between mate-retention strategies and violence against women. Also a self-report method was used and so there is a chance that people could have given answers they thought were social desirable rather than truthful ones which reduces the validity of the study’s results.

Research into mate-retention also has a very useful real world application as use of these strategies can now alert families and friends to the fact that violence is a big possibility in the future and therefore it is more likely it can be stopped in advance of any violence occurring.

All research done into mate-retention strategies has a large gender bias as it has all been focused on males and usually on male-male and male-female mate retention and can therefore not be generalised to other situations.

Infidelity can also be the cause of violence and aggression in males. This is where voluntary sexual relations take place between a married individual and someone other than their partner. This when taken part in by a married woman can lead to cuckoldry as they then often expect their partner to invest in any offspring that occur from the infidelity. Camilleri and Quinsey (2009) supported Infidelity and cuckoldry leading to aggression and violence when they found that men convicted of partner rape where more likely to have experienced infidelity and/or cuckoldry prior to this occurring than those who were convicted of non-sexual partner abuse. This would support aggression as an evolutionary response as the males are trying to stop cuckoldry which would cause them to invest all their resources in another man’s genes rather than his own which would have been terrible for our ancestors in our EEA.

The evolutionary explanation also fails to say why some cultures require male violence for social status whereas in other cultures it damages this. If aggression was the result of evolution surly it would be universal which suggests that there may be more complex factors involved in aggression, such as genetic or neural factors rather than just evolutionary ones.