Neural and Hormonal explanation

Question 1

What are the two biological explanations of aggression?

Answer 1

1) Neural and Hormonal
2) Genetics

Question 2

What are the 3 Neural and Hormonal explanations?

Answer 2

1) The limbic system
2) Serotonin
3) Testosterone

Question 3

What is the limbic system?

Answer 3

• Complex system of nerves and networks in the brain
• Controls basic emotions (fear, pleasure, anger)
• Controls drives (hunger, sex, dominance)

Question 4

What are the two structures involved in the limbic systems?

Answer 4

1) amygdala
2) hippocampus

Question 5

What is the role of the amygdala?

Answer 5

Quickly evaluates the emotional importance of sensory information

Question 6

What happens if the amygdala is stimulated in animals?

Answer 6

In animals, electrical simulation of the amygdala results in aggressive response

Question 7

What happens if amygdala is removed?

Answer 7

If removed no aggression is demonstrated

Question 8

What happens if the amygdala is removed in a dominant monkey?

Answer 8

Loss of dominance within that group

Question 9

What is the role of the hippocampus?

Answer 9

• Involved with the formation and consolidation of the long term memory
• Animals can compare the current threat with similar past experiences and respond appropriately

Question 10

What happens if the hippocampus is damaged?

Answer 10

The nervous system fails to put situations into a meaningful context, leading the amygdala to respond inappropriately.

Question 11

What has been found in young offenders?

Answer 11

Impaired hippocampal functioning has been found in violent offenders

Question 12

What is wrong with evidence from young offenders?

Answer 12

lacks population validity , not all offenders are violent

Question 13

What can be argued about the limbic system?

Answer 13

Can be argued it is reductionist

Question 14

What does serotonin inhibit?

Answer 14

Serotonin inhibits the firing of the amygdala

Question 15

What does low levels of serotonin mean?

Answer 15

• Low levels of serotonin removes the inhibitory effect
• Individuals are less able to control aggressive impulses

Question 16

What is testosterone linked with?

Answer 16

Aggressive behaviour

Question 17

What did Sapolsky (1998) do?

Answer 17

• Removed source of testosterone in diff species and found lower levels of aggression
• Subsequently, reinstating normal levels of testosterone leads to return of aggressive behaviour

Question 18

True or False: Testosterone levels reach peak in young males then decline

Answer 18

True

Question 19

What did Dabbs et al (1987) measure and find?

Answer 19

• Measured the salivary testosterone in violent and non-violent criminals.
• Criminals with history of primarily violent crimes had higher testosterone

Question 20

A03 Evaluate the role of the amygdala in aggression.

Answer 20

• Strength of the role of the amygdala in aggression is that there is supporting evidence.
• Pardini et al (2014) found the volume of amygdala can predict aggressive responses and behaviours.
• Carried out a longitudinal study on male ppts from child to adulthood with varying levels of violence
• Subjected to brain MRI at 26
• Low amygdala volume show more aggression and violence
• Suggests that the amygdala plays an important role in evaluating the emotional importance and sensory information, also the volume size.

Question 21

A03 Research support for the serotonin deficiency hypothesis

Answer 21

• Duke et al (2013) carried out meta analysis of 175 studies, involving 6,500 ppts.
• Found a small inverse relationship between serotonin levels and aggression
• Found that the magnitude of the relationship varied with the methods used to assess serotonin functioning.
• Only other-reported aggression was positively correlated to serotonin functioning.
• Suggests that the relationship between serotonin and aggression is more complex than originally thought.