26.10.23 Forensic Psychology - Biological explanations: Genetic and Neural

Question 1

What do the genetic explanations for crime suggest?

Answer 1

Would be offenders INHERIT gene or COMBINATION of genes PREDISPOSING them to committing a crime

Question 2

What demonstrates the importance of genes?

Answer 2

TWIN studies

Question 3

Procedure for Christiansen study

Answer 3

• Investigated OVER 3,500 twin PAIRS in DENMARK
• Offender behaviour CHECKED against DANISH POLICE records

Question 4

Findings for Christiansen study

Answer 4

• Found CONCORDANCE rates for OFFENDER behaviour of 35% MZ MALES
• 13% for DZ MALES

Question 5

Conclusion for Christiansen study

Answer 5

Not just BEHAVIOUR which is inherited but also UNDERLYING PREDISPOSING traits

Question 6

Findings for Crowe study

Answer 6

• ADOPTED children whose BIOLOGICAL mother had CRIMINAL record **more likely **to have CRIMINAL RECORD by age of 18
• ADOPTED children whose BIOLOGICAL mother did not less likely to have CRIMINAL RECORD by age of 18

Question 7

Procedure for Tiihonen et al study

Answer 7

GENETICALLY analysed almost **800 FINNISH **offenders

Question 8

Findings for **Tiihonen et al **study

Answer 8

• Suggested TWO genes may be associated with VIOLENT crime
• MAOA and CDH13
• MAOA REGULATES serotonin in brain
• Linked to AGGRESSIVE behaviour
• CDH13 linked to substance ABUSE and ADHD
• 5-10% SEVERE VIOLENT crime linked to these genes

Question 9

What does the diathesis-stress model of offending behaviour suggest?

Answer 9

Offending behaviour caused by combination of GENETIC PREDISPOSITION and BIOLOGICAL or PSYCHOLOGICAL trigger

Question 10

Give an example of a biological and psychological trigger

Answer 10

Being raised in DYSFUNCTIONAL environment or having CRIMINAL role models

Question 11

What do the neural explanations for offending behaviour suggest?

Answer 11

May be NEURAL differences in brain STRUCTURE of offenders and non offenders

Question 12

What has Raine conducted?

Answer 12

Multiple studies of APD brain

Question 13

Findings of Raine’s studies

Answer 13

Individuals with APD have REDUCED activity in their PREFRONTAL CORTEX

Question 14

Findings of Raine and his colleagues

Answer 14

11% REDUCTION in VOLUME of GREY MATTER in PREFRONTAL CORTEX of people with APD compared to controls

Question 15

What are mirror neurons?

Answer 15

• Neurons which FIRE when animal PERFORMS an action and when animal OBSERVES same action performed by other
• ‘MIRROR’ behaviour observed

Question 16

Procedure for Keysers study

Answer 16

• Asked offenders to EMPATHISE with person experiencing PAIN on CLIP
• Only then did their EMPATHY reaction ACTIVATE
• Controlled by MIRROR NEURONS

Question 17

Conclusion of Keysers study

Answer 17

APD individuals do not completely LACK empathy
May have ‘NEURAL’ switch they turn ON or OFF
Unlike ‘NORMAL’ brain which has EMPATHY switch PERMANENTLY turned on

Question 18

What is a strength of the diathesis-stress model of offending?

Answer 18

Evidence supporting it

Question 19

Evidence supporting it

Answer 19

• Mednick et al
• Studied 13,000 DANISH adoptees
• When neither BIOLOGICAL nor ADOPTIVE
  parents had CONVICTIONS, % of
  adoptees that did VERY LOW
• Figure INCREASED when either parent did
• Figure further INCREASED when BOTH
  parents did
• Shows GENETIC INHERITANCE important
  in OFFENDING but **ENVIRONMENTAL **
  influence also key

Question 20

What is a limitation of using twin studies as genetic evidence?

Answer 20

• Assumption of EQUAL environments
• Shared environmental assumption applies more to MZ twins than DZ twins
• Looks same so treated MORE similarly affecting their BEHAVIOUR
• HIGHER concordance rates for MZs in TWIN studies because treated SIMILARLY

Question 21

What is a strength of the neural explanation?

Answer 21

Evidence for link between CRIME and FRONTAL lobe

Question 22

Evidence for link between crime and frontal lobe

Answer 22

• Kandel and Freed
• Reviewed evidence of FL DAMAGE and
  ANTISOCIAL behaviour
• People with damage show IMPUSLIVE
  behaviour, EMOTIONAL INSTABILITY and
  failure to LEARN from mistakes
• FL associated with PLANNING behaviour
• Brain DAMAGE may be CAUSAL factor in
  offending behaviour

Question 23

What is a limitation of the neural explanation?

Answer 23

Link between NEURAL DIFFERENCES and APD may be COMPLEX

Question 24

Link between neural differences and APD may be complex

Answer 24

• Farrington et al
• Studied group of MEN scoring HIGH on
  PSYCHOPATHY
• All experienced RISK factors during
  childhood such as PHYSICAL neglection and
  being raised by CONVICTED parent
• Early CHILDHOOD experiences may have
  caused APD
• Relationship between neural difference,s
  APD and offending COMPLEX
• May be OTHER variables contributing