Biological explanations: Genetic and neural explanations

Question 1

Genetics

Answer 1

Genes consist of DNA strands
DNA produces’instructions’ for general physical features of an organism and also specific physical features.
These may impact on psychological features (intelligence and mental disorder).
Parents –> offspring

Question 2

Genetic explanations for crime suggest…

Answer 2

… would-be offenders inherit a gene, or combination of genes, that predispose them to commit crime

Question 3

Twin studies

Answer 3

LANGE - 13 identical (MZ) and 17 non identical (DZ) twins
1 in each pair had served time in prison
Found = 10 of MZ twins but only 2 of the DZ twins had a co-twin who was also in prison
Concluded = genetic factors must play a predominant part in offending behaviour.

Question 4

Adoption studies

Answer 4

CROWE - adopted children who had a biological parent with a criminal record had a 50% risk of having a criminal record by the age of 18, whereas adopted children whose mother didn’t have a criminal record only had a 5% risk.

Question 5

Candidate genes

Answer 5

Analysis of 900 offenders revealed abnormalities on 2 genes that may be associated with violent crime
- MAOA gene (controls dopamine and serotonin)
- CDH13 (linked to substance abuse and attention deficit hyperactivity disorder)
Individuals with this high risk combination were 13 times more likely to have history of violent behaviour.
- research has not been replicated

Question 6

Diathesis-stress model

Answer 6

If genetics do have influenced on offending, effects of environment aswell.
criminal behaviour may come about through combination of genetic predisposition and biological pr psychological trigger
e.g. criminal role models

Question 7

Neural explanations

Answer 7

May be neural differences in the brains of criminals and non-criminals.
investigated individuals diagnosed with antisocial personality disorder - APD

Question 8

Antisocial personality disorder - APD

Answer 8

associated with reduced emotional responses, a lack of empathy for feelings of others, and is a condition that characterises many convicted criminals.

Question 9

Prefrontal Cortex

Answer 9

individuals with antisocial personalities have reduced activity in the prefrontal cortex - part of brain that regulates emotional behaviour.
Found = 11% reduction in volume of grey matter in the prefrontal cortex of people with APD compared to controls.

Question 10

Mirror Neurons

Answer 10

KEYSERS - only when criminals were asked to empathise ( with a person depicted on fil experiencing pain) did their empathy reaction (controlled by mirror neurons) activate.
Suggests APD individuals are not totally without empathy, but may have neural ‘switch’ that can be turned on and off, unlike the ‘normal’ brain