Biology Explanantion 1: Inherited Criminality

Question 1

Adrian Raine (1993)

Answer 1

Reviewed research on the delinquent behaviour of twins and found 52% concordance for MZ twins compared with 21% for DZ twins. Genes may predispose individuals to criminal behaviour.

Question 2

What are the two genes linked to criminal behaviour?

Answer 2

MAOA and CDH13

Question 3

Han Brunner et Al. (1993)

Answer 3

Analysed the DNA of 28 male members of a Dutch family who had histories of impulsive and violent criminal behaviours such as rape and attempted murder. The researchers found that the men shared a particular gene that led to abnormally low levels of MAOA.

Question 4

How does diathesis-stress link to criminality ?

Answer 4

Capsi et al. assessed anti social behaviour at age 26 and found that 12% of men with the low MAOA gene had experienced maltreatment but were responsible for 44% of violent convictions.

Question 5

How can criminal genes possibly cause differences if the brain or differences in key neurotransmitters?

Answer 5

Adrian Raine (2004) cited 71 brain imaging studies showing that murderers, psychopaths and violent individuals have reduced functioning in the prefrontal cortex, the area involved in regulating emotions. Lowered activity in this area is associated with impulsiveness and loss of control.

Question 6

What do researchers suggest about low levels of neurotransmitter serotonin?

Answer 6

May predispose individuals to impulsive aggression and criminal behaviour, partly because this neurotransmitter normally inhibits the prefrontal cortex.