Role of hormones on human behaviour

Question 1

What are hormones?

Answer 1

Chemical messengers that travel throughout the body in the bloodstream.
They take longer to relay their message to areas of the body compared to neurotransmitters.

Question 2

How does testosterone affect aggression?

Answer 2

Testosterone increases aggression.
Exposure to it before birth is thought to lead to increased aggression.

Testosterone affects levels of serotonin, affecting our moods negatively and, therefore, increasing aggression.

In males, increased testosterone increases their competitive responses, especially in relation to sex, leading to increased aggression.

Testosterone is thought to increase activity in the amygdala and hypothalamus, making a person more likely to respond to situations with aggression.

Question 3

How does cortisol affect aggression?

Answer 3

Cortisol increases with stress.
Low cortisol levels lead to aggressive behaviour as they have an under-aroused autonomic nervous system (ANS), so aggression is needed to increase arousal. This leads to an increase in cortisol and, therefore, stress.

Cortisol also helps to inhibit aggressive behaviour, so low cortisol levels do not have the same mediating effect.

Question 4

Name 2 strengths of hormones as an explanation for aggression.

Answer 4

Dabbs et al. - measured testosterone levels in 89 male prisoners and found the levels of testosterone were higher in males who had committed violent crimes compared to those who hadn’t

Adelson - stimulated aggression control centres in rats and found increased stress hormones in their blood, so stress can lead to aggression and vice versa.

Question 5

Name 2 weaknesses of hormones as an explanation of aggression

Answer 5

Animals are in artificial situations when aggression is studied, and their social behaviour is not the same as humans, so the results may not be generalisable to humans.

Gerra et al. - found that ppts that had higher levels of aggression also had higher levels of cortisol