Biological explanation to offending: Genetic

Question 1

Describe the study by Tiihonenen et al and what it shows

Answer 1

Genetic analysis of 800 Finnish offenders
5-10% of severe violent crimes are attributed to 2 genes

MAOA and CDH13 gene

Question 2

Describe the role of the MAOA gene in causing offending behaviour

Answer 2

MAOA gene regulates MAOA enzyme which breaks down serotonin.
Variation of this gene MAOA - L.

Low activity links to less serotonin broken down, increasing levels of serotonin in brain and resulting in poor impulse control

Question 3

Describe the role of the CDH13 gene in causing offending behaviour

Answer 3

Involved in signalling between cells

Linked to substance abuse and ADHD which can lead to offending behaviours

Question 4

Describe the twin studies by Christiansen (1977)

Answer 4

• 3500 twin pairs in Denmark studied
• 35% concordance MZ
• 13% concordance DZ

Question 5

Describe the diathesis stress model

Answer 5

Genes produce a genetic predisposition to a behaviour
This interacts with the environment.
A trigger brings out the behaviour

Question 6

Strengths of genetic explanation to offending behaviour

Answer 6

• Research to support (Tiihonenen)
• Research to support Diathesis stress model.

Question 7

Describe research to support the diathesis stress model

Answer 7

Mednick et al studied 13,000 Danish adoptees who Vhad convictions

Conviction rates

13.5% (Biological or adoptive parents had no convictions)

20% (one biological parent convicted)

24.5% (adoptive and biological parent convicted)

Question 8

Weakness of genetic explanation to offending behaviour

Answer 8

• Twin studies issues (Christiansen)
• Biologically deterministic