Aggression

Question 1

What are the components of the limbic system?

Answer 1

Hypothalamus, Hippocampus, Amygdala

Question 2

Where does the amygdala have a role in the limbic system?

Answer 2

aggression, eating, drinking, and sexual behaviours

Question 3

Where does the hippocampus have a role in the limbic system?

Answer 3

memory, learning, and emotion

Question 4

What role does the hypothalamus have in the limbic system?

Answer 4

regulates processes in the body through its connection to the CNS, ANS and endocrine system

Question 5

What was the concordance rate of monozygotic twins?
(aggressive and anti-social behaviour)

Answer 5

87%

Question 6

What was the concordance rate of dizygotic twins?
(aggressive and anti-social behaviour)

Answer 6

72%

Question 7

KEY STUDY
What happened in Caspi et al MAOA genes study?

Answer 7

1037 participants (more girls than boys)
longitudinal study of 26 yrs (birth to adulthood)

Method: recorded the genetic makeup (high or low MAOA activity) and noted upbringing - any abuse or maltreatment as children

Question 8

Findings of Caspi MAOA gene study

Answer 8

Low MAOA = no effect alone - only in cases of abuse
(abused MEN 3x more likely to commit violent crime)

Question 9

Conclusions of Caspi MAOA gene study

Answer 9

• MAOA makes men more likely to be violent but only if maltreated as children
• less noticeable in girls
• gene is found on the X chromosome –> girls have xx (cancel out)

Question 10

What is the limbic system?

Answer 10

Subcortical structures in the brain (including the hypothalamus and amygdala) thought to be closely involved in regulating emotional behaviour

Question 11

What is serotonin?

Answer 11

A neurotransmitter with widespread inhibitory effects throughout the brain

Question 12

What is testosterone?

Answer 12

A hormone from the androgen group (sex hormones) that is produces mainly in the male testes (and in smaller amounts in the female ovaries)

Question 13

What are the impacts of reduced serotonin levels?

Answer 13

• increased firing of neurons in the orbitofrontal cortex
• reduced self-control
• increase of impulsive behaviour (inc aggression)

Question 14

A study to support the role of the amygdala

Answer 14

Gospic et al (2011)
- participants subject to mild provocation
- aggressive reactions showed (through fMRI scans) a fast and heightened response in the amygdala

Question 15

Why are men typically more aggressive than women?

Answer 15

Males produce much higher concentrations of testosterone than females, and this may therefore lead to higher levels of aggression

Question 16

When are testosterone levels the highest in males?

Answer 16

Adolescents (puberty)

Question 17

What is the role of testosterone in behaviour?

Answer 17

• regulates social behaviour via its influence on certain areas of the brain