Biological Explanation Flashcards
Concordance rates, twins and adoption (genetic)
- Christansen: Looked at 3500 twins offender behaviour. Found 35% MZ concordance rate = must be a genetic criminal
- Crowe: If a child has a criminal mother, they a 50% risk of factor of being a criminal, compared to 5% children with no criminal parents.
Candidate genes
They were found for criminal behaviour (VIOLENT only)
- MAOA and CDH13 regulate serotonin (low activity of these is associated with aggressive behaviour and substance abuse).
- 5-10% of all violent rimes committed in Finland were due to abnormalities in these genes.
Diathesis- stress
Diathesis: A genetic pre-disposition
Stress: An environmental stress that triggers the criminal behaviour.
Epigenetics: the criminal gene is activated by the stressor. (E.g. criminal role model)
Neural
⬆️ Noradrenaline = violence and aggression
⬆️ Testosterone = violence and aggression
⬇️ Serotonin = leads to impulsive behaviour
Antisocial personality disorder (neural)
⬇️resting heartrate,
- birth complications that damage the brain, mother
- smokes/drank during pregnancy, leading to APD.
- They lack empathy, this leads to a decreased emotional response.
- a study found an 11% reduction in the volume of grey mtter in the pre-frontal cortex (this area regulates emotions)
AO3 general
+ The definition of crime changes BUT this explanation is fixed. However, this explanation doesn’t explain all crime, just violent and aggressive crimes.
- The genetic explanation ignores the influence of the environment and social factors that can shape a criminal, including neglect etc and is therefore a reductionist explanation. Furthermore, as concordance rates are not 100% there must be other factors contributing to criminal personality.
AO3 genetic
+ Twins: it’s hard to disentangle nature and nurture, they are socialised the same so social learning theory would be an alternate and valid potentially explanation (observing and imitating), the same is true for observing criminal parents.
+ Adoption studies: Many extraneous variables: age of adoption, degree of care from family etc.
- small sample size due to twins not being the norm, reduces scientific value and means it is harder to draw valid conclusions from a smaller sample size.
AO3 Neural
+ Researched people with frontal lobe damage. Found their behaviour was impulsive and that they were usually emotionally unstable and could not learn from their mistakes. HOWEVER this may explain offending but not cause it.
⬆️(Not sure about this one)
- suggests that offending behaviour is innate or cannot be controlled which gives offenders an excuse and raises issues with the criminal justice system.
- A study was done on adult males with APD who had a convicted parent and were neglected physically as children. Early experiences could cause this APD or it could be as a result of both neural and environmental factors. (Interactionist approach and could be explained by diatheses-stress. Relationship between neural and genetic causes with environmental on APD are complex so a reductionist, purely biological approach is inappropriate and other factors should be considered.
