Neural Explanation

Question 1

What is a neural explanation to aggression?

Answer 1

Refers to explaining aggression through brain structures and neurotransmitters

Question 2

What is the limbic system?

Answer 2

• An area of the brain that helps to coordinate behaviours that satisfy motivational and emotional urges (aggression)
• Key structures in the limbic system associated with aggression are the hippocampus and amygdala

Question 3

Describe the role of the amygdala in aggression

Answer 3

• Responsible for quickly evaluating the emotional importance of sensory information and prompting an appropriate response
• If certain areas of the amygdala are stimulated electrically, aggression may be produced.
• If these areas are removed, the aggressive response to stimuli doesn’t happen

Question 4

Describe the role of the hippocampus in aggression

Answer 4

• It’s involved with the formation of long-term memories so allows the comparison of current threat with similar past experiences
• Impaired hippocampal function prevents the nervous system from putting things into a relevant context, causing the amygdala to respond inappropriately with aggression to a sensory stimuli

Question 5

Describe research support for the role of the hippocampus in aggression

Answer 5

Boccardi et al found that habitually violent offenders exhibited abnormalities of hippocampal functioning

Question 6

What is the effect of normal serotonin levels?

Answer 6

• Serotonin exerts a calming, inhibitory effect on neuronal firing in the brain and typically inhibits the firing of the amygdala
• It reduces aggression by inhibiting responses to emotional stimuli

Question 7

Describe the role of low serotonin levels in aggression

Answer 7

• It removes the inhibitory effect so individuals are less able to control aggressive behaviour, called the ‘serotonin deficiency hypothesis’.
• So when the amygdala is stimulated by external events, it becomes more active causing the person to act impulsively and making aggression more likely

Question 8

Give evaluation for the neural explanation of aggression (overlooks the complex role of serotonin)

Answer 8

• A criticism of the serotonin deficiency hypothesis is that it overlooks the complex role of serotonin in aggression
• Evidence shows that those with the MAOA gene are likely to be more aggression. The MAOA-L gene is linked to higher serotonin levels as it struggles to break down serotonin, leading to more aggression, which contradicts the serotonin deficiency hypothesis
• Therefore, the role of serotonin in aggression isn’t fully understood and the serotonin deficiency hypothesis may be an oversimplified explanation for aggression

Question 9

Give evaluation for the neural explanation of aggression (research support for the amygdala)

Answer 9

• e.g. Pardini et al carried out a longitudinal study of male participants from childhood to adulthood. Some of them with histories of violence were subjected to a brain MRI. The results showed that those with lower amygdala volumes were more aggressive.
• Furthermore, this relationship between amygdala volume and aggression remained even after confounding variables were controlled
• This suggests that there’s a strong link between the amygdala and aggression

Question 10

Give evaluation for the neural explanation (research support for the hippocampus)

Answer 10

• Raine et al studied 2 groups of violent criminals; some who faced convictions (‘unsuccessful psychopaths’) and those who evaded the law (‘successful psychopaths’). The ‘successful’ group were calculating while the former group were more impulsive, which is why they were caught.
• MRI scans showed asymmetries in the hippocampus in the ‘unsuccessful’ group.
• This suggests that abnormalities in the hippocampus may lead to aggression, which is outlined in the neural explanation of aggression