Biological theory of aggression - the role of evolution and natural selection

what is evolution? and why does it happen?

changes in inherited characteristics in a biological population over successive generations, It happens because genetic differences between organisms create variation. Variations arise because genes from parents combined and also due to spontaneous mutations in jeans. Individuals who possess characteristics that help them to stay alive and reproduce are the ones who pass their jeans onto the next generation.

What is natural selection?

Inherited traits that enhance an animals reproductive success are passed on to the next generation and thus ‘selected’ Whereas animals without such traits are less successful at reproduction and their traits are not selected ‘ Survival of the fittest’

What is the EEA?

Environment of Evolutionary Adaptiveness is the ancestral environment to which a species, including humans, is adapted, and the set of selection pressures that shape an adaption - For humans, this is assumed to be Hunter gatherer groups

What are evolutionary psychologists do?

• Look at fossil records to understand the EEA

• Speculate what type of behaviour would’ve been adapted there e.g. parental investment,mate choice

For the evolutionary determinants of mates choice what are the characteristics that men like? And what is the evolutionary explanation?

Hourglass figure and absence of wrinkles. The evolutionary explanation is that:

• Sexual maturity because the hourglass figure is greatly enhanced after puberty indicating a female is reproductive.

• Slim waste indicates absence of pregnancy – female who is already pregnant cannot be impregnated again

• Wrinkles may indicate female is no longer reproductive – post menopausal

Evolutionary determinant of meat selection what do women like and what is the evolutionary explanation?

Wealthy, tall and Dominant. The evolutionary explanation to this is:

• have resources necessary to provide all that is needed for healthy children

• Have the right qualities to protect them and offspring

• Have good genes to pass onto offspring

What are the evolutionary determinants of diet? What are the dietary choices and what is evolutionary explanation to this?

People crave food like sugar, cake, fries. Essentially sweet and fatty foods, People do not crave foods like water, potatoes, and . This is because we have evolved to crave high calorie foods because in the EEA are evolutionary ancestors would have needed to make the most of such food, in order to keep them going when food was in short supply

For the evolution as an explanation for aggression, Why is gaining territory and resources a reason for aggression?

What is the evidence of this in the EEA?

What is a modern day example?

Limited resources in EEA meant that those who successfully thought for food and shelter lived.

The evidence for this in the EEA is the early humans developed weapons that would have been useful in acquiring resources.

Modern day example is children bullying others for money or sweets, Crimes such as robbery, international warfare

What is the reason for defence against the attackers?

Evidence for this in the EEA

Modern day example

Aggression to protect themselves, mate and offspring attackers if they were to ensure survival of genes

Evidence for this an EEA – Ancient civilisations built wooden stockades and stone walls

Modern day example – Dated communities, security gates, soldiers at national Borders

Sexual jealousy/inflicting cost on same-sex rivals reason for aggression?

Evidence of this in the EEA

Modern day example

Males who aggressively defend and guarded females when another males competing for females attention out reproduced those who did not

Humans in all cultures form committed sexual relationships

Aggression from same-sex members to aid in competition for resources and mates

Negotiating status and power hierarchy as a reason for aggression?

Evidence for this in the EEA

Modern day example

Humans who regressive would be seen as stronger in a social group and so placed higher in the group

Chiefs give men special status and power in tribal societies, position may allow them to take more than one wife

Aggression to gain prestige and dominance, women attracted to dominance and powerful men

Mate selection as a reason for aggression

Evidence for this in the EEA

Modern day example

Successful females chose mates who provide provided good genes

Males who display aggressive traits more likely to be selected as mate because females would think they could provide better resources

Male to aggressive in business and successful in what they do a desirable mate

Why would a female being aggressive be an evolutionary disadvantage?

• Female spend long periods of time pregnant and looking after children for survival

• Would not make sense to put them in danger

• Female aggression is less physical and more verbal and emotional in nature

Evaluation of evolutionary explanations of aggression

…

Evidence

🙂– There is evidence e.g. Brendgen Found gender differences between males and females – provides some support for role of evolution and development of aggression

CA- Difficult to measure evolutionary mechanisms behind aggression as would need to measure a generations that has practical implications – less credible than explanations such as brain structure as explanation of aggression. Difficult to establish cause-and-effect

Strengths/shortcomings

😔– Reductionist – only explains aggression in terms of genetics does not look at other factors that can lead to aggression e.g. unconscious drives

CA- Reductionist allows focus on isolated variables leading to aggression at greater depth

🙂– Theory of aggression can explain individual differences in development of aggression e.g. gender differences in aggression

CA- Cannot explain why some females are physically aggressive and why some males may not be aggressive

Alternative

Does not take into account role of nurture so social learning theory would suggest that aggression is learnt through modelling behaviour of adult or aggressive – theory incomplete