Genetic and Neural Explanations Flashcards
Genetic explanations
- Candidate genes
- twin studies
- adoption studies
- diathesis stress
Candidate genes
TIHONEN ET AL
- MAOA-L
- CDH-13
- 800 ppts in Finland had links to these genes
MAOA-L
Linked to aggressive behaviour, regulates seretonin
CDH-13
Linked to susbtance abuse and ADHD
Twin studies
CHRISTIANSEN
- 3500 twin pairs concordance rates for offending behaviour
- 35% MZ concordance
- 13% DZ concordance
Adoption studies
MEDNICK
- 13000 male adoptees
- 13.5% had neither biological or adopted parents convicted
- 20% had one biological convicted parent
- 24.5% had both their adopted and biological parent convicted
Diathesis - stress
Caspi et al
- 500 boys
- only an offender if have MAOA-L gene variant and were maltreated as a child
Genetic AO3 + Mednick
Suggests both genes and environment have impact
- diathesis stress
Genetic AO3 - twin studies
- not 100% concordance in MZ twins
- assume equal environment
- cannot generalise as twins are abnormal
Neural explanations
- Antisocial Personality Disorder
- Low activity in prefrontal cortex
- Mirror Neurons not on
APD
Associated with low empathy and low emotional response
- many convicted offenders have an APD diagnosis
Low activity in PFC
RAINE ET AL
- more than 11% reduction in volume of grey matter in PFC of people with APD compared to non APD control
- PFC is the part of the brain associated with emotional behaviour
Mirror neurons not turned on
KEYERS
- when offenders asked to empathise they could but only when asked as mirror neurons are then acitvates
- APD means they do not experience empathy unless they turn on they mirror neurons
Neural AO3 + research support
KANDEL AND FREED
- impulsive behaviour, emotional instability, and inability to learn from mistakes in those with PFC damage
Neural AO3 - link with APD is complex
FARRINGTON ET AL
- males with high APD were raised by convicted parents and were physically neglects
- reducted PCF activity could be due to trauma
