biological explanations of offending behaviour: genetic and neural

Question 1

what are genetic explanations?

Answer 1

suggest offenders inherit a gene/combination which predispose them to commit crime

Question 2

twin study which illustrates the importance of genes

Answer 2

• christiansen 1977
• 3500+ twin pairs in Denmark
• concordance rates for offender behaviour: 35% for MZ + 13% for DZ males (slightly lower for females)
• all twins 1880-1910 in region in denmark
• behaviour + predisposing traits inherited?

Question 3

adoption study which illustrates the importance of genes

Answer 3

• crowe 1972
• adopted children - biological mother had criminal record
• 50% risk of having criminal record by 18
• adopted children with biological mother without criminal record - 5% risk

Question 4

which study investigates candidate genes?

Answer 4

• tiihonen et al 2015 - analysis - 800 finnish offenders
• MAOA + CDH13 may be associated with violent crime
• MAOA gene regulates serotonin in brain - linked with aggressive behaviour
• CDH13 - linked to substance abuse + ADHD
• when these genes found together - 13x more likely for offender - face history of violent behaviour

Question 5

what is the diathesis-stress model of offending?

Answer 5

• likely - genetics partly moderated by effects of the environment
• tendency towards offending behaviour may come through combo - genetic predisposition + biological/psychological trigger - ex. raised in dysfunctional family