Forensic Psychology - Biological Explanation

Question 1

What types of evidence support the existence of genetic explanations ?

Answer 1

twin studies
gene association studies

Question 2

Twin Studies - Lange

Answer 2

Compared concordance rates for prison sentences among 13 identical twins and 17 non-identical.
- 10/13 had both spent time in prison
- 2/17 on the non identical twins spent time in prison
Concordance rates show it’s higher in MZ than DZ twins - supports role of genetics

Question 3

Adoption studies - Mednick

Answer 3

Looked at 14,427 adopted kids and compared the likelihood that a child would grow up to engage in criminal activity if their biological or adoptive parent were convicted criminals.

Question 4

What did the adoption studies suggest?

Answer 4

Having a biological parent who is a criminal is a better predictor of whether the child will go on to be a criminal than if adoptive parents are criminal.
- Supports role of genetics further.

Question 5

What does candidate genes mean?

Answer 5

There is no single criminal gene, several have been linked with criminal behaviour

Question 6

MAOA-L gene is what?
Evidence

Answer 6

It is linked with aggressive behaviour which is linked with criminal behaviour.
Brunner - studied a family w/ a history of aggressive and criminal behaviour - found all the males had the gene
Shows the gene could be a partial explanation

Question 7

Strength - Genetic Explanations

Answer 7

P: Supporting evidence
E: Twin studies - strength
Supports the genetic explanation

Question 8

Weakness of genetic explanations - determinism

Answer 8

P:It is deterministic
E: They say that a person’s genes are what cause criminal behaviour not free will.
E: This raises moral issues - it is hard to hold someone morally responsible for criminal actions as being a criminal is (in part) due to genetics
L: if someone hasn’t chosen criminal actions, you can’t then punish them.

Question 9

Biological Explanations - weakness : methodological issues w/ twin studies

Answer 9

P: It is possible that identical twins are more likely to be treated similarly in comparison to non identical twins.
E: This similarity in environment may be at least partially responsible for the higher concordance rates for criminality among identical twins