GENETICS

Question 1

TWIN STUDIES

Answer 1

• 50% of the variance in aggressive behaviour is explained by genetic factors other 50% is the shared environment/experiental factors such as parent treatment and non-shared eg different friend groups
• Emil coccaro found that the heritability of aggression depended on behaviour 47% variance from in direct physical aggression was genetics and verbal only 28%

Question 2

ADOPTION STUDIES

Answer 2

• Soo Rhee and Irwin Waldman conducted a meta-analysis of adoption studies on a direct aggression and anti-social behaviour
• genetic influence explain 41% of the variance

Question 3

MAOA GENE

Answer 3

• MAOA enzyme in the brain which breaks down seretonin
• determined by the MAOA gene a dysfunction can lead to deficiency of MAOA
• a low activity or ‘warrior gene’
• Han Brunner studied 28 males of a Dutch family all been involved in violent criminal behaviour Eg attempted murder rape assault all had the gene and corresponding deficiency in their brains

Question 4

DARK TRIAD

Answer 4

• Delroy Paulus and Kevin Williams found a collection of traits which are associated with an averse personality
• machiavellianism: ability to manipulate for personal benefit
• Narcissism: vanity self entitlement and inflated view of ones self
• psychopathy: emotional coldness, callousness, impulsitivity and lack of empathy
• Adrian Furnham found they are all highly heritable in a twin study 64% psychopathy 59% narcissism and 31% machiavellianism