Forensics - Biological: Genetics and Neural Flashcards
(9 cards)
Genetic explanation
One or more genes predispose individuals to criminal behaviour
- Twin studies
Genetic: MAOA gene
MAOA-L - less MAOA produced
Affect neurotransmitter levels (serotonin& dopamine)
Can’t break down NT well - large quantities in the brain - impulsiveness & loss of control
Genetic support - Han Brunner et al
28 males from Dutch family
Involved in impulsive aggressive criminal behaviour
Had abnormally low levels of MAOA in brains & MAOA-L gene
Supports role of MAOA in aggression
Genetic support - Christiansen
3586 twin pairs in Denmark
Males concordance - 35% MZ, 13% DZ
Females concordance - 21% MZ, 8% DZ
Genetic - Diathesis-stress model
Someone may have biological tendencies (predisposition) towards crimes, need an environmental trigger to actually become a criminal
Neural explanation
How structures of the brain may be different in criminals
Difference in NT levels - high levels of noradrenaline linked to violence
Focuses on people with antisocial personality disorder
Neural support - Raine: prefrontal cortex
PET scanning 71 criminals
Abnormalities in parts of the brain in violent criminals
Most criminals in study diagnosed with APD
Reduced activity in prefrontal cortex (emotional behaviour, decision making)
Don’t suffer from guilt or remorse, impulsiveness, loss of control
Neural - Raine: Limbic System
41 violent murderers & 41 non-murderers
PET scan
Less activity in prefrontal cortex & areas of the limbic system (amygdala, hypothalamus, hippocampus)
Less control over impulsive behaviour
Biological evaluation
Strengths:
Research support from gene & adoption studies
Diathesis-stress model takes into account both biology & environment
PET scans are scientific method
Weaknesses:
Biologically reductionist
Deterministic
Criminality may run in families - so do other risk factors associated with criminality (pro-criminal attitudes)
Not stereotype children from ‘criminal families’
Only violent crimes - petty crimes?
