Genetic and Neural Explanation

Question 1

What is the genetic explanation

Answer 1

Offending behaviour is inherited as 1 or more genes predispose people to commit crimes

Question 2

What is Lange et al Twin study

Answer 2

Looked at 13 MZ twins (identical) and 17 DZ twins where 1 twin in each pair went to prison
. Found 10 MZ twins but only 2 DZ twins were both in prison

Question 3

What is Christiansen Twin study

Answer 3

Studied 87 MZ twins and 147 DZ twins and found concordance rate of 33% for MZ and 12% for DZ

Question 4

What is lygosity

Answer 4

Whether twins are MZ and DZ, checking zygosity was problem with early twin studies

Question 5

Candidate Genes

Answer 5

Genetic analysis of 900 Finnish offenders revealed abnormalities in 2 genes that may associate with violent crime:
1. MAOA gene = controls dopamine/serotonin in brain (linked to aggression)
2. CDH13 gene = linked to substance abuse and ADD

Individuals with combo 13x more likely to have history of violence

Question 6

Diathesis Stress Model

Answer 6

Diathesis = genetic predisposition
Stress = environmental trigger
^ combo leads to tendency of criminal behaviour

Question 7

What is the neural explanation

Answer 7

Focus on areas of brain and nervous system, and action of neurotransmitting

Question 8

Prefrontal Cortex

Answer 8

Raine conducted many studies on brains of those with APD, several dozen show those with APD have reduced activity in PFC - 11% reduction in volume of grey matter

Eval: neuroplasticity = did environmental factors cause neural changes

Question 9

Mirror Neurons

Answer 9

Found only when criminals were asked to emphathise with person depicted on film in pain did their empathy (controlled by mirror neurons) activate
. Individuals with APD not totally without empathy but may have neural ‘switch’ that can be turned on and off

Question 10

Evaluation (Strengths)

Answer 10

Support for Diathesis Stress Model
- Study of 13,000 Danish adoptees, concordance rates should be the same for convicted bio parents no matter if adoptive parents were convicted

Question 11

Evaluation (Weaknesses)

Answer 11

Problems with twin studies
- early studies poorly controlled, judgement related to zygosity may lack validity
- twins reared in same environment - major confounding variable

Biological reductionism
- criminality is complex, inappropriate and overly simplistic
^ MZ pairs don’t show 100% concordance