Genetic Explanation Flashcards
(6 cards)
1
Q
Who conducted twin studies for genetic explanations?
A
- Christianson studied over 3500 twin pairs in Denmark and found concordance rates for offender behaviour of 35% fir identical twins males and 13% for non-identical twin males (slightly lower for females)
- Data indicates that underlying predisposing traits are inherited
2
Q
Who conducted adoption studies for genetic explanations?
A
- Crowe found adopted children whose mother had a criminal record had a 50% risk of having a criminal record by the age of 18 otherwise they had a 5% risk
3
Q
Who investigated candidate genes for the genetic explanation of criminal behaviour?
A
- Tiihonen conducted a genetic analysis of almost 800 Finnish offenders and found some genes may be associated with violent crime
- MAOA gene regulates serotonin and is linked to aggressive behaviour
- CDH13 gene is linked to substance abuse and attention deficit hyperactivity disorder
- 5-10% of severe violent crime in Finland is attributable to MAOA and CDH13 genotypes
4
Q
What is the Diathesis-stress model (genetic and neural)?
A
- the influence of genetic are at least partly moderated by the environment
- a tendency towards offending behaviour may come through a combination of genetic predisposition and a trigger
5
Q
What is one limitation of twin evidence?
A
- One limitation is the assumption of equal environment because twins are raised together
- May apply more to MZ twins than DZ twins because MZ twins look identical
- Concordance rates for MZs in twins studies may simply be because they are treated more similarly
6
Q
What is the support for diathesis-stress?
A
- A study of 13,000 Danish adoptees was conducted by Mednick
- When neither bio or adoptive parents had convictions, the percentage of adoptees that did was 13.5% and the figure rose to 20% when either bio parents had convictions and 24.5% when both adoptive and bio parents had convictions
- Genetic inheritance plays a role in offending but environmental influence also important
