Biological Exp: Genetic & Neural

Question 1

Genetic Explanations - Aggression

Answer 1

1) Psychologists have stated that there is a link between aggression and criminal behaviour.

1) Twin studies like Christiansen (1977) found that:
- Male identical twins had 35% concordance for criminality.
- Male non-identical twins had only a 12% concordance rate.
- Females had a 21% concordance for identical.
- And 8% for non-identical.

Question 2

Diathesis-Stress Model

Answer 2

1) If genes have an influence on offending, this influence is likely to be at least partly moderated by environmental factors.

2) The diathesis-stress model suggests that a tendency to offending behaviour is due to a combination of:
* Genetic predisposition (diathesis).
* A biological or psychological stressor or ‘trigger’ (e.g. criminal role models or dysfunctional upbringing).

Question 3

Adoption Studies

Answer 3

Adoption studies examine concordance rates of criminal activity.

1) Mednick et al. (1984) studied criminal behaviour in adopted children.
2) 14 000 Danish adopted children, concordance rates of criminality were compared between: Adopted parents & Biological parents.

13.5% of adopted children had a criminal conviction with biological or adoptive parents with no criminal convictions.
15% of adopted children had a conviction with at least one adoptive parent who had a criminal conviction.
20% of adopted children had a conviction with at least one biological parent who had a criminal conviction.
25% of adopted children had a conviction rate with at least one biological parent and one adoptive parent with a criminal conviction.

Question 4

Evaluation of Mednick

Answer 4

STRENGTHS:

1) Adoption studies are important in the nature vs nurture debate as they can separate out the genetic and environmental influences. Therefore, this is a powerful study.

2) The sample size was very large, increasing the validity of the results.

Question 5

Neural Explanations - Raine

Answer 5

1) Raine PET scanned 41 murderers and 41 control participants.
2) There were differences in glucose metabolism in areas of the brain:
Prefrontal cortex.
The corpus callosum.

–> Raine et al. found evidence of neural differences in murderers compared to controls.
The evidence supports a link between brain dysfunction and violent criminal activity like murder.

Question 6

Strength of Model

Answer 6

SCIENTIFIC

1) Many studies, including Lombroso, Mednick, Jacobs, Christiansen, and Raine, provided a lot of evidence of the role of genetics and biology in criminality.

–> Biological theories can be scientifically tested as proved by the above studies.
Scientific testing makes theories more reliable.

Question 7

Limitation of Exp

Answer 7

BIOLOGICAL DETERMINISM// REDUCTIONIST

1) The biological approach suggests offending behaviour is determined by factors which cannot be controlled so no
responsibility.

2) However, justice system is based on individual responsibility.

–> This suggests we should ‘excuse’ some people but, ultimately, this is not possible because then many could claim no responsibility.