Biological explanations of offending behaviour: Genetic and neural

Question 1

Define ‘Epigenetics’

Answer 1

The material in each cell of the body that acts like a set of ‘switches’ to turn genes on or off.

Question 2

Define ‘Genetic explanations’

Answer 2

The likelihood of behaving in a particular way is determined by a person’s genetic make-up.

Question 3

What are the twin studies for genetic explanations?

Answer 3

52% concordance for Mz
21% for Dz

Question 4

What are the two genetic explanations for this approach?

Answer 4

Candidate genes and diathesis stress model

Question 5

Explain the candidate genes

Answer 5

Brunner et al looked at 28 male members of a Dutch family that had a history of violent crimes and found that when analysing their DNA they all shared a gene that led to low levels of MAOA.

Question 6

What are the two main candidate genes?

Answer 6

MAOA and CD13

Question 7

CD13 research

Answer 7

Finnish study, Tiihonen et al, 900 offenders low MAOA activity and low CD13 activity, makes up 5-10% of violent crimes in Finland

Question 8

What does the diathesis- stress model suggest?

Answer 8

Suggests one or a few genes alone won’t determine behaviour, instead it is epigenetics, genes switched on or off due to environmental factors, maltreatment in childhood.
12% of men in longitudinal study has low MAOA, but were responsible for 44% of violent crime

Question 9

Define ‘Neural explanations’

Answer 9

They involve areas of the brain and nervous system and the action of chemical messengers in the brain known as neurotransmitters in controlling behaviour.

Question 10

Explain the regions of the brain responsible for aggressive behaviour

Answer 10

Prefrontal cortex - associated with regulating emotion and controlling moral behaviour.
lowered activity in this area is associated with impulsiveness and loss of control.
Limbic system - set of subcortical structures that are linked to emotion and motivation.
Abnormal asymmetries in the limbic system have been linked to criminal behaviour.

Question 11

Explain the role of neurotransmitters in criminal behaviour

Answer 11

Serotonin - low levels predispose individuals to impulsive aggression and criminal behaviour.
Serotonin normally inhibits the prefrontal cortex - dopamine hyperactivity may enhance this effect.

Noradrenaline - very high and very low levels are associated with aggression, violence and criminality

Question 12

Outline the evaluation points for genetic and neural explanations

Answer 12

Cause or effect relationship
Strength of genetic explanations
Reductionist explanations