Genetic & neural explanations for crime

Most studies into the role of genetics have tended to use what techniques?

Twin & adoption studies

What term refers to the degree of similarity between two things (e.g. two twins or children & biological/adoptive parents) ?

Concordance

Name two candidate genes that have been linked to crime

MAOA & CDH13

Where was Tiihonen et al.’s study completed & how many offenders were used?

• Finland

• 900

The MAOA gene is responsible for controlling what in the brain?

Dopamine & serotonin

What has CDH13 been linked to?

Substance abuse & ADHD

Within the Finnish sample, individuals with the high-risk combination of candidate genes were how many times more likely to have a history of violent behaviour?

13

What percentage of all violent crimes are said to be due to abnormalities in one of the two candidate genes (MAOA & CDH13) ?

5-10%

What theory considers that genetic explanations may also have an environmental component?

The diathesis-stress model

What is an example of an environmental trigger that may be required to result in criminal behaviour?

Being raised in a dysfunctional environment or having criminal role models

Which part of the brain has been found to be linked with aggression & therefore, criminal behaviour?

Amygdala

Most of the research into neurophysiological explanations of crime in humans has focused upon people with what (also known as psychopaths)?

Antisocial personality disorder (APD)

Those with APD show what type of behaviour?

No emotion & empathy for others

Studies using EEGs suggest that brain activity in APD sufferers is different to that of the normal population leading to which hypothesis?

Maturation retardation hypothesis

What does the maturation retardation hypothesis propose?

The brain of an APD sufferer is immature & child-like, explaining their impulsivity & self-centredness

What biological feature may those with APD lack based upon research into empathy for others?

Mirror neurons switched on

Describe Keysers et al.’s study

• Only when criminals were asked to empathise with a person depicted on film experiencing pain, did their empathy reaction (controlled by mirror neurons in the brain) activate

• This suggests that APD individuals are not totally without empathy but may have a neural 'switch'  that can be turned on & off, unlike the 'normal' brain which has the empathy switch permanently on

Discuss the genetic and neural explanations of offending behaviour (16 marks)

Write your AO1 paragraph

• Genetic explanations for crime propose that criminality may be influenced by inherited genes, which are investigated by twin & adoption studies which examine concordance rates. For example, Crowe found that adopted children who had a biological parent with a criminal record had a 50% risk of having a criminal record by age 18, compared to 5% whose biological mother didn’t have a criminal record.

• Neural explanations propose that there are neural differences between criminals & non-criminals, particularly in those with antisocial personality disorder (APD), which is characterised by a lack of empathy for others. The limbic system & the amygdala have been linked to aggression. EEG studies support the maturation retardation hypothesis, which argues that the brain of an APD sufferer is immature & child-like, explaining their impulsivity & self-centredness.

• However, research also suggests that APD sufferers can experience empathy but more sporadically. For example, Keysers et al. found that only when criminals were asked to empathise, with a person depicted on film experiencing pain, did their empathy reaction (controlled by mirror neurons in the brain) activate. This suggests that APD individuals are not completely without empathy but have a neural 'switch'  that can be turned on & off, unlike the 'normal' brain where the empathy switch is permanently on.

Discuss the genetic and neural explanations of offending behaviour (16 marks)

Write your strength AO3 PEEL (Raine et al.)

• Point: One strength of neural explanations is that there is research evidence in support from neuroimaging studies.

• Evidence: For example, Raine et al. compared brain structures in 41 violent offenders (murderers) with a matched control group of non-murderers using PET scans, which measured glucose metabolism during tasks.

• Explain: Results found lower activity in the amygdala & pre-frontal cortex, which are associated with emotional regulation & self-control, explaining why these individuals are more impulsive & less able to regulate aggression.

• Link: Therefore, this increases the validity of neural explanations by linking brain differences to criminality.

Discuss the genetic and neural explanations of offending behaviour (16 marks)

Write your limitation AO3 PEEL (British legal system)

• Point: One limitation of genetic & neural explanations is that they are not consistent with the way in which the British legal system operates.

• Evidence: For example, Tiihonen et al.’s genetic analysis of 900 Finnish offenders revealed abnormalities on the MAOA gene (controls dopamine & serotonin in the brain & is linked to aggression) & CDH13 (linked to ADHD & substance abuse). Results found that individuals with this genetic combination were 13 times more likely to have a history of violence.

• Explain: However, in a court of law, offenders are held morally accountable & responsible for their actions, meaning biological determinism may provide excuses for criminality.

• Link: Therefore, this raises ethical & legal dilemmas when prosecuting criminals & may allow offenders to mitigate their own liability & intent (mens rea)

Discuss the genetic and neural explanations of offending behaviour (16 marks)

Write your limitation AO3 PEEL (Osborne & West)

• Point: One limitation of genetic & neural explanations is that they suffer from biological determinism, as they fail to consider environmental influences.

• Evidence: For example, Osborne & West found that 40% of the sons of criminal fathers had criminal convictions by age 18, compared to 13% of the sons of non-criminal fathers.

• Explain: Although this suggests a genetic influence, crime also co-occurs with environmental factors (e.g. poverty, social deprivation, mental illness & criminal role models), making it difficult to establish cause & effect.

• Link: Overall, genetic & neural explanations are overly simplistic, as crime likely results from interactions between biological & environmental factors, as highlighted by the diathesis-stress model.