Evolutionary explanations of human aggression

What is evolution?

The gradual change in inherited characteristics over generations, leading to variation in members of the same species over time.

How does evolution occur?

By natural selection, favoured adaptations geared towards the survival in the particular environment.

How does aggression relate to evolution?

Aggression is a characteristic which increases survival chances and therefore enhances reproductive success.

What is the aggressive gene?

MAOA

Explain the aggressive gene as a evolutionary explanation of aggression

Aggression is a behaviour that has been passed down from our ancestors that needed this behaviour for survival. The MAOA gene, aka the warrior gene, has been linked to aggression. Therefore, individuals today might be more aggression due to inheriting a low-functioning version of this gene.

Explain aggression as a tool to assert dominance as a evolutionary explanation of aggression

In challenging environments, aggressions would help our ancient ore gain territory, resources and negotiate status. The aggressive behavioural traits were used in hunting and to provide food for others. Moreover, appropriating resources of a rival makes the, weaker and the aggressor stronger - so, they have a survival advantage.

Explain the use of aggression for mate retention as a evolutionary explanation of aggression

Buss (1988) argued that males have developed strategies for mate retention. These include direct guarding (restricting movements of a female partner), and negative inducements (threats of violence to prevent the female partner from ‘straying’). This would ensure the male’s genes are passed on and not their rivals genes.

Strength of the theory?

Supportive evidence from Chester (2015) to support the link between genetics and aggression. Chester (2015) took a sample of female saliva samples and found a positive correlation between a low functioning MAOA gene and aggression levels. Therefore, evolutionary explanations may be able to explain aggressive behaviour in humans.

Weakness of the theory?

Research (eg- Chester, 2015) looking at the link between evolution and aggression is only correlational. We can only observe, not manipulate, the variables involved in evolution, so we cannot establish cause and effect between evolution and aggression. Therefore, other theories for why people are aggressive, such as social learning theory, cannot be ruled out as we don’t know the credibility of evolutionary theories.