Biological explanation: Genetics and Neural explanation Flashcards
Genetic explanations for crime
It suggests that offenders inherit a gene or a combination of genes that predispose them to commit a crime. The evidence comes from twin studies which help separate genes from the environment (nature-nurture).
Raine et al’s study on twins
Reviewed research on the criminal behaviour of twins and found a 52% concordance rate for MZ twins and a 21% concordance rate for DZ twins.
Support for twin studies (can use as evaluation) (even more twin studies)
Lange investigated 13 MZ and 17 DZ twins where one of the twins in each pair had several time in prison. Lange found that 10 of the MZ twins but only 2 of the DZ twins had a co-twin who was also in prison. Lange concluded that genetic factors must play a part in offending behaviour
There were also adoption studies to support the genetic explanation
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 the age of 18, whereas adopted children whose parent didn’t have a criminal record only had 5% risk.
This further illustrates the importance of
genes in offending behaviour.
What two genes are responsible for Criminal behaviour
MAOA-controls dopamine and serotonin and has been linked to aggressive behaviour
CDH13-Linked to substance abuse and ADHD
Abnormalities in these genes were found to be responsible for violent crime in a Finnish study by Tiihonen et al (2015) on 900 offenders.
They found those who had a high risk combination were 13 times more likely to have a history of violent behaviour.
How might you use the diathesis stress model to explain offending behaviour?
If genetics have a role in offending, it would therefore be likely that this is in part moderated by the effects of the environment. A tendency to engage in offending behaviour may come about through interactions with both genetic predispositions and psychological triggers.
E.g. being raised in a dysfunctional environment or having criminal role models.
Neural explanations of Offending behaviour
Most of the evidence comes from people with anti social personality disorder. APD is associated with lack of empathy and reduced emotional response.
What does abnormality in prefrontal cortex show about the neural explanation for offending
Raine conducted studies with people with APD brains. These people have reduced activity in their prefrontal cortex (regulates emotional behaviour).
Furthermore Raine et al also found 11% reduction in the volume of grey matter in the Pre-Frontal Cortex of people with APD
Mirror neurons
Criminals with APD can experienece empathy but do so more sporaducally than the rest of us. Keysers et al found that only when criminals were asked to empathise with a person on a film did their empathy reaction (controlled by mirror neurons) activate.
What does mirror Neurons show about criminals
Suggests APD criminals are not totally without empathy, but may have a neural switch that can be turned on and off unlike the brains of normal people who always have the empathy switch on permanently.
