neural and hormonal explanations of aggression

Question 1

what is aggression?

Answer 1

a behaviour aiming to harm someone physically or psychologically

reactive aggression = a response to a perceived threat
proactive aggression = a response in anticipation of a reward

Question 2

neural: the limbic system

Answer 2

• a set of neural structures in the centre of the brain, such as the amygdala and the hypothalamus which are key to aggression
• it plays a key role in how we respond to environmental threats and challenges, controlling emotional behaviour like aggression

Question 3

the amygdala

Answer 3

• plays an important role in the production of emotions as it is involved in how we monitor and react to environmental cues
• also responsible for moderating testosterone levels

Question 4

the hypothalamus

Answer 4

• responsible for the regulation of the autonomic nervous system, which regulates responses to emotional circumstances
• damage here can result in inappropriate aggressive responses to a perceived threat

Question 5

the prefrontal cortex

Answer 5

• the limbic system has connections to the prefrontal cortex
• regulates social behaviour and aggressive responses, feelings are monitored and interpreted here to trigger a physical response
• damage here reduces the inhibition of the amygdala, causing higher levels of aggression

Question 6

neural: neurotransmitters

Answer 6

• the inhibitory neurotransmitter serotonin works on the frontal areas of the brain to inhibit the firing of the amygdala, it also has a calming influence on the brain
• reduced levels of serotonin in the orbitofrontal cortex reduces self-control, meaning people cannot control their impulsive behaviours

Question 7

hormones

Answer 7

• high levels of the male hormone testosterone have been associated with aggression
• it peaks in young adolescent men, and promotes muscle strength and is responsible for the sex drive

Question 8

the effect of cortisol on testosterone

Answer 8

• cortisol is a hormone in the response to stress
• low levels are linked to aggression as high levels of it block the influence of testosterone on the body

Question 9

give a strength of neural explanations of aggression
1/2

Answer 9

kluver and bucy (1939) removed the main areas of the limbic system in rhesus monkeys and found they displayed an absence of emotional, motor and vocal reactions associated with situations that elicit fear or anger. they also lost the social understanding of the group hierarchies and would try to fight the larger more dominant members of the group. this shows the importance of the limbic system in regulating aggression

COUNTER = however, the difference between animal and human physiology raises the question as to whether this research can be generalised to humans

Question 10

give a strength of neural explanations of aggression
2/2

Answer 10

ferrari et al (2003) support the role of serotonin in aggression. allowed adult male rats to fight another rat at the same time for 10 days, on the 11th day the rats weren’t allowed to fight. found that the rat’s dopamine levels increased by 65%, and serotonin decreased by 35%. even though the rats weren’t fighting, it altered their brain chemistry

COUNTER = issues with cause and effect. do low serotonin levels cause aggression or are they a response to being aggressive

Question 11

give a strength of hormonal explanations of aggression
1/1

Answer 11

wagner (1979) supports the role of testosterone in aggression. he castrated mice and their aggression levels decreased, supporting the idea that testosterone is implicated in aggression

COUNTER = only provides correlational support (only a relationship between lowered testosterone and lowered aggression)