Genetic Explanations

Question 1

Who conducted the first twin study to investigate the relationship between genetics and offending behaviour?

Answer 1

Lange

Question 2

Who did Lange investigate in his twin study?

Answer 2

13 identical and 17 non-identical where one twin had spent time in prison

Question 3

What did Lange find in his twin study?

Answer 3

10 of the identical twins but only 2 of the non-identical twins had a co-twin also in prison.

Question 4

Who conducted adoption studies into genetic explanations of offending behaviour?

Answer 4

Crowe

Question 5

What did Crowe find in adopted children?

Answer 5

Adopted child + biological parent with criminal record = 50% risk of criminal record by 18

Adopted child + non-criminal mother = 5% risk

Question 6

What is the diathesis-stress model and what does it suggest about criminality?

Answer 6

A tendency towards criminal behaviour may come through combination between genetic predisposition and biological/psychological trigger.

Question 7

Who conducted a genetic analysis of 900 offenders and candidate genes?

Answer 7

Tiihonen

Question 8

Which two genes did Tiihonen identify as having an association with violent behaviour?

Answer 8

MAOA and CDH13

Question 9

What does the MAOA gene control?

Answer 9

Dopamine and serotonin production in the brain.

Linked to aggressive behaviour

Question 10

What is the link with CDH13 and offending behaviour?

Answer 10

Linked to substance abuse and ADHD

Question 11

What did Tiihonen find?

Answer 11

Within his sample, individuals with a combination of these genes were 13x more likely to have a history of violent behaviour.