Forensics: Biological Approach - Genetic

Question 1

What does the genetic explanation suggest?

Answer 1

Whether there is a gene for criminal behaviour that predisposes them to crime.

Question 2

What was Tiihonens study on candidate genes?

Answer 2

He found 2 genes associated with violent crime. MAOA gene which controls dopamine and serotonin (which has been linked to aggressive behaviour) and CDH13 gene which has been linked to substance abuse and attention deficit disorder.
- individuals with this high risk combination were 13x more likely to have a history of violent behaviour. - analysis consisted of almost 900 offenders.
—> however, this research has not been replicated

Question 3

What does the Diathesis stress model suggest?

Answer 3

Genetics may have some effect, but it has to be affected by the environment

Question 4

What did Christiansen find studying twins?

Answer 4

Examined over 3,500 twin pairs in Denmark and identified concordance rates of criminal behaviour
- found MZ=35% and DZ=13% in males and MZ=21% and DZ=8% in females.
—> the rates are low, suggesting the environment plays a large part in criminal behaviour, also difference between male and female raises questions about gender in criminal behaviour.

Question 5

What did Raine also find with Twin studies?

Answer 5

Did a meta analysis of 13 studies and found MZ= 52% and DZ= 21%
—> this shows a link between offending behaviour and genetics

Question 6

What was Brunners study on a family?

Answer 6

He conducted a study on a large family in the Netherlands, a number of which had been responsible for various counts of anti-social and criminal behaviour, such as attempted rape, exhibitionism and arson.
- found the males had a genetic condition (later known as ‘Brunners syndrome’). It results in lower intelligence levels (family studied had an average IQ of 85) and causes a deficiency in MAOA
- this means individuals can inherit genetic conditions which make them more prone to offending behaviour.

Question 7

What did Crowe find conducting an adoption study?

Answer 7

Compared a group of children whose biological mother had a criminal record, to a control group of those who did not.
- found 50% of the children also had a criminal record by the time they were 18, yet control, only 5%.
—> suggest that regardless of the changed environment, children seemed biologically predisposed to criminality.

Question 8

What did Mednick also find conducting an adoption study?

Answer 8

Looking at 140,000 adoptees criminal records, found 13% criminal behaviour with adopted parents that had prior criminal records, 20% brought up with non-criminal adoptive parents but biological parents had criminal records and 24% when both adoptive and biological had criminal records.
—> concordance rates where higher for biological parents, suggesting genetic element to criminal behaviour.

Question 9

What’s some evaluation for the genetic explanations?

Answer 9

• twin and family studies dont rule out environmental impacts - results could be due to social learning since they are occupying the same environment
• adoption studies can rule out the effects of the environment, helps to see a clearer genetic link
• yet adopted child syndrome is a term to explain behaviours in adopted children relating to their adoptive status (e.g. problems in bonding, attachment disorders, lying, stealing, etc)
• Brunners research used a specific case study, so not generalisable or representative of the whole population - genetic makeup is unique to the family.
• nature, yet seen as reductionist due to the ignoring of nurture and external influences such as parenting culture and social learning.