Neural And Genetic Explenations (forensics)

Question 1

Raines research

Answer 1

Compared 27 psychopaths to 32 non
Psychopaths = 18% volume reduction in amygdala + 11% reduction of grey matter in PFC (lack empathy, guilt)

Compared 41 violent murderers to 41 non
Used PET scans - found differences in PFC and limbic system (associated with regulating emotions)

Question 2

Keysers research

Answer 2

When offenders asked to empathise they did = mirror neurons activated
Suggesting those with APD may have a neural switch

Question 3

Evaluation of neural explanations

Answer 3

+ Kandel and Freed - found people with damage to the pre frontal cortex tended to show impulsive behaviour, emotional instability and inability to learn from mistakes (prefrontal is also associated with planning behaviour)

• Cause and effect, Farrington - found offenders who scored high on psychopathy also experienced high risk factors, e.g convicted parent or neglect

Question 4

Tiihonen research

Answer 4

Candidate genes - MAOA and CDH13
Found people with a combination of these genes were 13x more likely to have a history of violent behaviour, and 5-10% of violent behaviour in Finland was found to be attributable to the MAOA and CDH13 genes

Question 5

Christiansens research

Answer 5

Used a sample of around 3500 Danish twin pairs and found a concordance rate between MZ twins of 35% and DZ twins 13%, therefore suggesting there is a link between criminal behaviour and genetics

Question 6

Crows research

Answer 6

Found that adopted children who had a biological parent who had been convicted before were at a 50% risk of having a criminal record themselves, where’s adopted children who’s mother didn’t have a criminal record only had a 5% risk

Question 7

Diathesis stress model

Answer 7

An interactionist approach
Criminal behaviour may be biologically predisposed, but is triggered by environmental factors, such as having criminal role model or being raised in a dysfunctional environment

Question 8

Evaluation of genetic explanations

Answer 8

+ Mednick et al - 13000 Danish adoptees, found that when both adoptive and biological parents combined had convictions, the chance that the adoptee also had been convicted was 24.5% - therefore, giving validity to the diathesis stress model as an interactionist approach

• Difference in concordance rates reflects differences in environment, e.g MZ twins more likely to be brought up the same/similar