Forensics - Biological explanations

Question 1

Historical approach: Atavistic from

Answer 1

Lombroso - criminals are less evolved with innate features that indicate criminality in different ways

Question 2

Lombroso’s research

Answer 2

• Examined features of around 4000 criminals & skulls of 400 dead criminals
• Shared common characteristics inc:
  + Pronounced jaw
  + Large ears
  + High cheekbones

Question 3

Strengths of atavistic form

Answer 3

+ Scientific (uses theory of evolution & biological findings over morality -> coined term criminology & started further research)
+ Predict behaviours (interventions can be put into place to prevent criminality)

Question 4

Limitations of atavistic form

Answer 4

• Racism (features were commonly attributed to people of African descent -> suggested they were criminals and boosted eugenic attitudes)
• Contradictory evidence (Goring 3k offender/non-offenders -> no evidence of distinct features)
• Methodological issues (no control group in Lombroso’s study -> issues with confounding variables)

Question 5

Genetic explanation

Answer 5

Predisposition to crime inherited from genes from a family member (considers diathesis-stress model, adoption, twin and candidate genes)

Question 6

Christiansen’s twin study (genetic)

Answer 6

• 3500 twin pairs with offending behaviour in Denmark born between 1880-1910

Findings (concordance rates):
MZ twins: 35% M, 21% F
DZ twins: 13% M, 8% F
Genes must be involved for MZ to have higher rates

Question 7

Crowe’s adoption study (genetic)

Answer 7

Adoptees with biologically criminal mothers had a 50% of being criminals by 18 (compared to 5% in control group)

Question 8

Genes linked to criminality (genetic)

Answer 8

MAOA -> warrior gene, linked to aggression, violence & impulsivity, breaks down neurotransmitters using enzymes i.e. dopamine & serotonin (MAOA-L -> unregulated neurotransmitters)

CDH13 -> links to substance abuse & ADHD, development & function of nervous system

Question 9

Neural explanation

Answer 9

Behaviour is predisposed by the nervous system & brain structures -> anti-social personality disorder

Question 10

Raine et al’s study of brain activity (neural)

Answer 10

PET scans of 41 murderers & control of 41 non-murderers

Findings: significant differences in certain areas
- Prefrontal cortex: lower activity = lower self control (impulsivity)
- Limbic system: amygdala lacks fear & hippocampus increased aggression (violence)
- Corpus callosum: problems with controlling/expressing emotions (regulation)

Increased risk of committing violence (predispositions)

Question 11

Mirror neurons (neural)

Answer 11

React to actions & express empathy if there is an understanding of the intention (research into APD - sporadic empathy)

Question 12

Strengths of genetic & neural explanations

Answer 12

+ Study supports
Genetic: Christiansen, Crowe, Mednicke
Neural: Kandel & Freed (frontal lobe damage = inability to learn from mistakes, impulsivity, emotional instability -> all predispositions)
+ Biological determinism (predictions are able to be made & create interventions [predictive validity])

Question 13

Limitations of genetic & neural explanations

Answer 13

• [HOWEVER] Biological determinism (cannot be held responsible for their actions -> Mobley defense)
• Correlational (mutations on MAOA gene does not always guarantee criminality)
• Complex (Farrington et al -> high APD scoring individuals had other risk factors such as early experiences - not just biology at play)
• Issues with studies (twin/adoption - treated identically/later in life adoptions -> can genes be the only thing?)