Scenario Your have been in a long-term relationship for 3 years. You have decided to move in together. Your best friend has just told you that when they were out one evening they saw your partner passionately kissing another person. What would you do?

Jealousy and aggression Infidelity Unfaithfulness of sexual partners. Sexual infidelity: Any behaviour involving sexual contact i.e. kissing, touching, sexual intercourse Emotional infidelity: Formation of affectional attachment to another person, can involve flirting, intimate conversations Jealousy Emotional response to anticipated loss of affection and/or status

Evolutionary explanations of sexual jealousy and infidelity If you were creating your own dating advertisements what would you be looking for? Read the dating advertisements Pick out the key words. Are there any differences between what the males are looking for and what the females are looking for?

Why do men and women express jealousy differently? Need to compete with other males for access to choosy females to ensure reproductive success Lower status men are willing to take greater risks by using aggression or face genetic extinction. Human males cannot risk wasting investment on offspring who are not their own so they should show more jealous violent aggression relating to female fidelity- both towards the male competitors and their long-term female mates if infidelity is suspected especially if the female is young and reproductively valuable If the female is unfaithful the man faces paternity uncertainly (Infidelity threatens reproductive success) What about reconstituted families, adoption and fostering? It creates sexual jealousy and uncertainty about paternity.

Mate - Retention Strategies Research argues that men have developed strategies to deter their mate from leaving or adultery Research: Shackelton et al found a positive correlation between mate retention strategies and violent acts

Human females can always guarantee that their offspring are their own and compete with other females for the quality of men rather than for the availability. Women take fewer risk with violence and use more indirect form of aggression. If a male is unfaithful the female partner risks losing his time, resources, energy, protection and commitment to her children. 40% of domestic violence victims are men in 2009 according to the British Crime Survey. Reproductive success is threatened by emotional jealousy and concerns about access to resources to support self and offspring.

emotional vs. sexual infidelity Why a difference ? One explanation for why men are thought to be more concerned about sexual infidelity is based on the assumption that men can have sex without emotional involvement whilst for a woman; sex and emotional involvement are linked. Males would think that if their partner had sex with another man, this would also suggest an emotional link to the man and a potential risk of another man impregnating the woman. This is also thought to explain why females are more concerned about emotional infidelity since this poses the greater threat for being left alone. The theory suggests that if females are abandoned, they will not have a partner to protect them, provide resources and energy and hence could put their child at risk. For this reason female jealousy may lead women to attack any woman trying to “steal her man”.

Evolutionary explanation for jealousy leading to aggression (AO1) Mate retention strategies are techniques used, such as holding hands in public, threatening violence to potential rivals or an unfaithful partner, that may have evolved because of sexual jealousy. The theory also suggests that if females are abandoned, they will not have a partner to protect them, provide resources and energy and hence could put their child at risk. For this reason female jealousy may lead women to attack any woman trying to “steal her man”. This is how infidelity and jealousy link to aggression.

Practice exam question Briefly outline infidelity and jealousy as evolutionary explanations of aggression. (4 marks)

AO1: knowledge and understanding Key points might include: ensuring reproductive success. Infidelity threatens reproductive success for men. It creates sexual jealousy and uncertainty about paternity. In women, reproductive success is threatened by emotional jealousy and concerns about access to resources to support self and offspring. These provide motivation and target for aggression. Individually you have 5 minutes to write an answer to the question.

Modal answer Evolutionary theory explains that infidelity triggers an emotional state and disrupts status quo. In females infidelity of a male partner causes emotional jealousy and concerns about whether he will have the time, resources/money to support her and possible offsprings and so threaten her reproductive success, and fail to provide conditions for a child to thrive. Thus aggression that prevents infidelity is adaptive. In males infidelity in female partner triggers sexual jealousy and uncertainty about paternity. Aggression associated with infidelity is based on suspicion. Jealousy is an adaptive behaviour to ensure exclusivity and keep ones mate. In males it involves mate tending and guarding including aggression to prevent infidelity.

So… What does the research say? How does the research link to the theory?

Now lets… evaluate the evolutionary explanation of aggression.