Evolutionary Explanations of Human Aggression

• Sexual jealousy refers to the emotions and behaviours involved in the perception (real or imagined) that one’s partner is engaging in infidelity or may be attracted to other males/females
• Anecdotal and research evidence suggests that males are more prone to sexual jealousy than females but females are more concerned about emotional infidelity (Kato, 2022) 
• An evolutionary explanation for heightened male sexual jealousy is the paternity uncertainty phenomenon i.e. a woman is always 100% sure that the child she is carrying is hers but her male partner (short of a DNA test) can never share that certainty
• Sexual jealousy may be adaptive in that it may ensure that the male is able to protect his genetic line i.e. by keeping close tabs on his partner he may scare off other males (and possibly scare his partner into not straying - a rather unpleasant and toxic concept to a 21st century thinker)
• Strategies employed by males to ensure that a female partner does not stray are, according to Wilson & Daly (1996) as follows:
  • Direct guarding - checking or even tracking her phone, watching for signs of interest in other men, asking her where she’s been, coming home at unusual times to see if she can be ‘caught’ engaging in suspicious behaviour
  • Negative inducements - letting her know the potential consequences of her leaving him (e.g. I’ll kill you/myself/the children if you leave me) which may (and, sadly, inevitably do) lead to physical violence (intimate partner violence, IPV)

‘Who is she texting? Why does she look so pleased?...’

Research which investigates evolutionary explanations of sexual jealousy

• Buss (2013) -  a review article in which the author concludes that sexual jealousy is a basic emotion which has evolved because it solves adaptive problems of mating
• Larsen et al. (2021) - a survey of 1266 high school students aged 16–19 which found that adolescent males found the sexual aspect of imagined infidelity more distressing than adolescent females did
• Schutzwohl (2006) -  two experiments which revealed that men are more occupied with thoughts about a mate’s sexual infidelity, whereas women are more occupied with thoughts about a mate’s emotional infidelity

• Bullying is a set of behaviours which are designed to intimidate, humiliate, control and torment another (usually more vulnerable) person
• A bully generally seeks power and it is this aspect of bullying that has led evolutionary psychologists to suggest that bullying is adaptive and brings with it evolutionary advantages for the bully (but clearly not for the victim!)
• Some research argues that bullying is universal and that it brings with it enhanced reproductive success as it is an outward display of strength, social status, success and resources -  both material and in terms of attractive traits (Hawle et al. 2007; Kolbert & Crothers, 2003) 
• The ultimate evolutionary drive behind (male) bullying is to attract females and, ultimately, to reproduce
• Female bullying is less likely to be openly direct and violent than that of males: it may include exclusion of the victim; spreading lies about the victim; verbal abuse; use of cyber-bullying 
• The evolutionary advantages of female bullying may be to secure resources by warding off competition for a male with resources which in turn ensures that any future offspring will be secure and will carry superior genetic material

Research which investigates evolutionary explanations of bullying

• Volk et al. (2012) - a review article which concludes that bullying may be an adaptive strategy that offers some benefits to those who engage in bullying behaviour
• Kolbert & Crothers (2003) - childhood bullying is used to establish dominance hierarchies in schools
• Campbell (1999) - a review article which suggests that females place a high value on enhancing their reproductive success, citing aggression as a form of ensuring this success

Why do some people bully others? Can it all be explained by evolution?

Evaluation of evolutionary explanations of aggression

Strengths

• There is a strong body of evidence that supports the concept of male sexual jealousy as an evolutionary drive (e.g. Shackleford et al. 2005)
• The understanding that bullying brings with it evolutionary benefits could be used to inform anti-bullying interventions i.e. by encouraging competitiveness in bullies so that they can display their positive qualities to potential mates without causing harm to others

Weaknesses

• Research by Hamel (2020) has shown that IPV is not confined to male-on-female violence: IPV can be and is perpetrated by women for a variety of reasons which could include sexual jealousy
• It is almost impossible to test evolutionary explanations as the ‘evidence’ is simply too far in the past to be able to operationalise or form meaningful conclusions from

Link to Issues & Debates:

Evolutionary explanations of aggression bring with them a large serving of alpha bias by suggesting (or even outright stating) that there are huge differences in male and female behaviour in terms of sexual jealousy and bullying. While it is true that males are more likely to be prone to these negative behaviours, they are by no means alone in this: females also commit IPV, feel jealous and act in a bullying manner but there is less research which supports female aggression using an evolutionary perspective.

The assumption that women are not aggressive is a deterministic view of human beings i.e. it does not allow women to express themselves using free will as the view of a ‘typical’ woman is that she will be caring, gentle, non-aggressive etc.The idea that it is ‘natural’ for a man to be aggressive but not for a woman to behave aggressively essentially results in the stigmatisation of aggression by females and means that women have to offer excuses or reasons for their aggression whereas for men this is not generally the case. This idea also resonates with the nature/nurture debate i.e. men are just naturally aggressive, it’s innate; women are just naturally caring, it’s innate.