Genetic explanations of crime

Question 1

What are twin studies?

Answer 1

They are good for identifying genetic behaviours. Examining monozygotic and dizygotic twins can show concordance rates that help to indicate possible genetic tendency

Question 2

What are concordance rates?

Answer 2

Percentages to show how many twin pairs share behaviours under observation

Question 3

What study supports twin studies and what was it about?

Answer 3

Christiansen - he examined 3500 twins in denmark and identified concordance rates for criminal behaviour
Male - MZ: 35%, DZ: 13%
Female - MZ: 21%, DZ: 8%

Question 4

What did the data of Christiansen’s study show?

Answer 4

• Males are more likely to commit crimes than females
• Both genders of MZ twins have higher concordance rates than DZ twins

Question 5

What study supported family studies?

Answer 5

Brunner et al - an analysis of a large family in the Netherlands, a large number of them had been responsible for various counts of anti social and criminal behaviour
Researchers found the males to have a genetic condition (brunner syndrome),
The condition results in lower intelligence levels and a deficiency in MAOA- linking to aggression
In conclusion the individuals can inherit genetic conditions which make them more likely to commit offending behaviour

Question 6

Criticisms of Brunner et al’s study

Answer 6

• Can’t be held accountable for genes: only one family and all commit similar crimes so upbringing may be the problem
• Ethnocentric: only one family in Netherlands so can’t explain other families criminal behaviours

Question 7

What was the aim of adoption studies?

Answer 7

Research in genetics can’t rule out the effect of the environment. How children are raised by parents or siblings is likely to be a factor to their behaviour. Adoption studies looked into children who have been adopted and been raised by adopted parents where there’s no genetic similarity

Question 8

What study supports adoption studies?

Answer 8

Crowe: compared a group of adopted children - their biological mother had a criminal record, to a control group of adopted children whose biological mother didn’t have a criminal record
If a biological mother had a criminal record - 50% of adopted children also had one by 18 years old, in the control group only 5% of children had a criminal record by 18
Suggests that regardless of the changed environment, children seemed biologically predisposed to crim

Question 9

Evaluation of adoption studies

Answer 9

Strength: scientific replicability - proven further as there will be many more adopted children with biological criminal mothers
Weakness: invalidity - 1 mother in the control group had a criminal record so likely to be higher due to emotions and masking in the adoption process