Biological explanations

• Outline the genetic explanation for offending behaviour.


  The genetic explanation proposes that offenders have inherited genes that predispose them to commit a crime e.g. a low-activity version of the MAOA gene.
• Outline the genetic explanation for offending behaviour.

  The MAOA gene is responsible for making enzymes that breaks down neurotransmitters such as dopamine and serotonin.

  A low-activity version therefore produces less enzymes so results in high levels of dopamine and serotonin.
• Outline the genetic explanation for offending behaviour.

  High levels of serotonin causes their receptors to become desensitized to its inhibitory effects, making neurons in the nervous system highly active.

  This causes feelings of agitation and restless, in turn, leading to impulsive crimes of aggression.

  Meanwhile, high levels of dopamine can lead to reward-seeking behaviour seen in crimes such as theft.
• Evaluate the genetic explanation for offending behaviour: supporting evidence. 


  E.g. Twin studies have found higher concordance rates for offending behaviour in MZ twins (who share 100% of their genes) than DZ twins (who share 50% of their genes). This is a strength because the higher likelihood of MZ twins both being offenders can be explained by their more similar genetics.
• Evaluate the genetic explanation for offending behaviour: supporting evidence from twin studies suffers from confounding variables. 


  This is because MZ twins are likely to share more similar environmental experiences than DZ twins due to always being of the same sex and looking more alike. As a result, they are likely to have the same friendship groups where both may be exposed to pro-crime attitudes and behaviour. This is a limitation because it suggests that offending behaviour can result from environmental experiences rather than genetics.
• Evaluate the genetic explanation for offending behaviour: adoption studies.

  They have found that adopted children who had a biological parent with a criminal record were found to have a higher risk of having a criminal record than adopted children whose biological parent did not have a criminal record, despite both being raised by non-criminal families. This is a strength because the children being at a higher risk of engaging in criminal behaviour if their biological parent was also a criminal can be explained by them inheriting criminal genes.
• Evaluate the genetic explanation for offending behaviour: too biologically deterministic.

  This is because it proposes the criminal behaviour is determined by biological factors (e.g. genes) that are outside of the individual’s control. This is a limitation because it leads to negative implications on the criminal justice system whereby we expect criminals to take

  responsibility for their crimes so they can be appropriately punished.
• Outline the neural explanation for offending behaviour.


  The neural explanation proposes that offending behaviour is caused by abnormalities in brain structure and/or function.
• Outline the neural explanation for offending behaviour.

  Brain scanning research has found that offenders have reduced activity in the prefrontal cortex, a brain area involved in decision making.

  Reduced activity in this area could therefore led to poor decision making and impulsive behaviour which is often seen in impulsive violent crimes.
• Outline the neural explanation for offending behaviour.

  Brain scanning research has also found that offenders have reduced activity in their amygdala, a brain area that processes emotions such as fear.

  Reduced activity in this area could result in individuals being less likely to recognize the fear they cause in their victim as well as the fear they should feel about potentially being imprisoned for any crime they commit.
• Evaluate the neural explanation for offending behaviour: supporting evidence. 


  E.g. brain scanning studies have found that men with lower amygdala volumes are more likely to be violent than men with average-sized amygdalas. In addition, brain scans on people with antisocial personality disorder have found that many of the individuals had reduced tissue and activity in their prefrontal cortex compared to controls. This is a strength as it supports the proposal that abnormalities in brain structure/function can lead to offending behaviour.
• Evaluate the neural explanation for offending behaviour: supporting evidence.


  E.g. TMS is a method used to send electrical impulses to the brain in order to increase neuron activity. Research using this technique has found that increasing activity in the prefrontal cortex reduces criminal intentions and increases perceptions of aggressive behaviour as being morally wrong. This is a strength as it supports the proposal that lower activity in the prefrontal cortex can contribute to offending behaviour.
• Evaluate the neural explanation for offending behaviour: fails to take into account individual differences.


  Criminal psychopaths typically do not have an underactive pre-frontal cortex, they are more likely to have increased activity, hence why they commit pre-planned crimes. While psychopaths may be cold and calculating ( reduced amygdala activity), non-psychopaths may have an overactive amygdala, explaining why commit impulsive crimes. This is a limitation because it suggests that the neural explanation cannot explain all offending behaviour.
• Evaluate the neural explanation for offending behaviour: biologically deterministic. 


  This is because it proposes the criminal behaviour is determined by biological factors (e.g. brain abnormalities) that are outside of the individual’s control. This is a limitation because it leads to negative implications on the criminal justice system whereby we expect criminals to take responsibility for their crimes so they can be appropriately punished.