Biological Explinations Flashcards
Twin studies
Lange (1930).
- 13 MZ and 17 DZ where one of the twins had serve prison time.
- 10 of the MZ, 2 of DZ had co-twins also in prison
- Genetic evidence
Role of frontal lobe (to do with crime)
- Impulse control
- Empathy
- Decisions
- Emotions
Adoption studies
Crowe (1972).
Found adopted children with a criminal parent had 50% chance of having criminal record by 18.
Adopted children without criminal mother only 5%
Candidate gene study
- Genome analysis of 900 offenders
- MAOA (dopamine and serotonin) and CDH13 (substance abuse and ADHD)
- high risk genetic combination are 13 times more likely to be criminal
What cognitive features can an abnormality on the MAOA gene associated with
- Impulse control
- Empathy
- Decisions
Outline ADP
- ADP (antisocial personality disorder) formerly psychopath
- Charactised by reduced emotion and lack of empathy
Diathesis-stress model
A tendency towards criminality is likely a combination of a genetic predisposition and a psychological trigger
Mirror neurones and APD
- When watching a film, empathy mirror neurones were only active when asked specifically to empathise
- Not without empathy but not switched on like in normal brains.
What did Raine find in APD brains
11% reduction of volume of grey matter compared to controls
Problem with twin studies
- Pool control, MZ or DZ classification based on appearance (low IValitidy)
- Small samples
- Most twins reared in same environment (confounding variable) as concordance rates due to environmental
Support for diathesis-stress model of crime
Mednick et al. (1984)
- Studied 13,000 danish adoptees
- Where neither biological or adopted parents convicted: 13.5% had CR
- 20% either bio parent
- 24.5% when both adoptive and bio
Problems with adoption studies
Children not separated straight away and much of life spent with bio parents anyway
Brunner
Bruner.
- Studied Dutch family with high rates of violent crime
- Men found to have faulty MAOA (enzyme) regulator gene
- Affected neurotransmitters
Biological reductionism/ determinism
Reductionism:
- Explaining crime at a neural level is too simplistic
- Although time runs in families so does social deprivation and poverty
- Also non 100% concordance shows not entirely environmental
Determinism
- Raised ethical issues if it is fact true that criminality is determined by biology
- Criminal system based off free will