Biological explanations: Genetic and neural explanations

Question 1

Genetic explanations

parts

Answer 1

Twin studies -Lange (1930)
Adoption studies -Crowe (1972)
Candidate genes -Tiihonen et al (2014)
Diathesis-stress model

Question 2

genetics

Answer 2

genes consist of DNA which determine physical features like eye colour but also neurotransmitter levels and size of brain structures which may impact on psychological features (like intelligence and mental disorder)-genes are inherited

Question 3

Genetic explanations

Twin studies

Answer 3

└illustrates the importance of genes
└Lange (1930)
└investigated 13 identical (MZ) and 17 non identical (DZ) twins where one of each pair had been in prison
└10/13 MZ were both in prison
└2/16 DZ were both in prison
└=concluded that genetic factors must play a role in offending behaviour

Question 4

Genetic explanations

Adoption studies

Answer 4

└Crowe (1972)
└found that adopted children who had a biological parent with a criminal record had a 50% risk of having a criminal record by 18
└5% risk if biological parent didn’t have a criminal record

Question 5

Genetic explanations

Candidate genes

Answer 5

└Tiihonen et al (2014)
└genetic analysis of almost 900 offenders
└2 genes that may be associated with violent crime
└MAOA gene (controls serotonin in brain, linked to aggressive behaviour)
└CDH13 (liked with substance abuse and ADHD)
└13 times more likely to have history of violent behaviour with this genetic combination
└study hasn’t been replicated

Question 6

Genetic explanations

Diathesis-stress model

Answer 6

└tendency of criminal behaviour may be due to a combination of a genetic predisposition and a biological or psychological trigger
└e.g. being raised in a dysfunctional environment or having criminal role models

Question 7

Neural explanations

parts

Answer 7

Prefrontal cortex- Raine et al (2000)

Mirror neurons - Keysers et al (2011)

Question 8

Neural explanations

Answer 8

└an explanation of behaviour in terms of functions of the brain and nervous system
└e.g. activity of hypothalamus, and neurotransmitters (e.g. serotonin, dopamine)
└most research in this area investigates people with antisocial personality disorder (psychopaths)
└lack of empathy and emotion

Question 9

Neural explanations

Prefrontal cortex

Answer 9

└Raine
└brain imaging studies of ADP brain
└have reduced activity in prefrontal cortex (regulates emotional behaviour)
└Raine et al (2000)
└11% reduction of grey matter in prefrontal cortex of people with ADP compared to controls

Question 10

Neural explanations

Mirror neurons

Answer 10

└Keysers et al (2011)
Empathy reaction (controlled by mirror neurons in the brain) only activated when criminals were asked to emphasise when watching a person on film experiencing pain
└=people with ADP have empathy, but neural switch can be turned on and off whereas normal peoples is always on

Question 11

Biological explanations: Genetic and neural explanations

strengths

Answer 11

Support for diathesis stress model of crime
└Mednick et al (1984)
└study of over 13,000 adoptees
└neither biological of adopted parents had convictions= 13.5% of adoptees did
└biological parents had convictions= 20% of adoptees did
└adoptive and biological parents had convictions= 24.5% of adoptees did
└data suggests inheritance plays an important role in offending
└so does environment
└=support for diathesis stress model of crime

Question 12

Biological explanations: Genetic and neural explanations
limitations
summary

Answer 12

Problems with twin studies

Problems with adoption studies

Question 13

Biological explanations: Genetic and neural explanations
limitations
Problems with twin studies

Answer 13

└early twin studies of criminality (e.g. Lange)
└poor control of if twins were MZ or DZ
└based on appearance not DNA
└=low validity
└twin studies have small sample sizes
└unusual sample
└can’t generalise to wider population
└most twins raised in same environment
└=confounding variable
└concordance rates may be due to shared experiences than genetics

Question 14

Biological explanations: Genetic and neural explanations
limitations
Problems with adoption studies

Answer 14

└unclear genetic and environmental influences in adoption studies e.g. Mednick et al
└children may have had a late adoption
└=spent much time with biological parents
└children may still have regular contact with biological parents after adoption
└Mednick et al
└study was regarding petty offences, not violent crime
└may not apply to more serious forms of crime