Biological Explanations of offending behaviour

• Neural explanation


  Explanation of behaviour in terms of dysfunction of the brain and nervous system
• Genetic explanation


  The DNA a person inherits from their parents may give them a predisposition to criminal behaviour
• Adoption studies

  • Adopted children whose biological mother had a criminal record had a 50% risk of having a criminal record whereas adopted children whose biological mother did not have a criminal record had a 5% risk
• Candidate genes

  • There are 2 genes associated with violent crime
  • The MAOA gene regulates serotonin and dopamine in the brain and having low levels can lead to aggressive behaviour
  • CDH13 has been linked to substance abuse and ADHD
  • 5-10% of severe crimes in Finland is caused by these genes
• Diathesis stress model

  • A tendency towards offending behaviour may come about through the combination of genetics and a biological and psychological trigger
• Research to support the diathesis stress model

  • Longitudinal study done on over 1,000 males from birth to adulthood over 20 years
  • Maltreated children who also had a low activity MAOA gene were more likely to develop antisocial behaviour
  • The genetics and the environment that work together to make someone criminal
• Neural Explanation

  • Evidence suggests there may be neural differences in the brains of offenders and non offenders
  • People develop antisocial personality disorder
  • APD is associated with reduced emotional response and a lack of empathy
• Prefrontal cortex research

  • 41 offenders that committed murder were compared to a control group
  • All their brains were scanned
  • The murderer's brains had reduced activity in the prefrontal cortex which regulates emotional behaviour
  • Another study found that those with APD have 11% reduction of grey matter in the prefrontal cortex
• Mirror neurons

  • Offenders can experience empathy but only in specific situations
  • They can only empathise when they are asked to empathise
  • APD individuals have a 'switch' than can be turned on and off
• AO3 Genetic Explanation: Issues with twin evidence

  • A limitation of twin studies is that they assume they have the same environments
  • As twins are brought up together it is assumed their environment is the same
  • This may only hold true to MZ twins as they are identical so may also be treated similarly by everyone
  • Concordance rates for MZ twins may be higher because they are treated more similarly
• AO3 Genetic Explanation: Support for diathesis-stress model

  • Study of 13000 Danish adoptees
  • When neither biological or adoptive parents had convictions the chances adoptees were convicted was 13.5%
  • When either parents had convictions it rose to 20% and rose to 24.5% when both parents had convictions
  • Genetic inheritance plays an important role in offending but environmental influence is also important providing support for the diathesis stress model
• AO3 Biological Explanation: Nature and Nurture

  • Both nature and nurture may play factors in contributing to criminal behaviour
  • There are biological implications to committing crime due to having low activity of the MAOA gene
  • The environmental implications may be social factors such as poverty and family
• AO3 Neural Explanation: Brain evidence

  • Supports for the link between crime and the frontal lobe
  • Reviewed evidence of frontal lobe damage and antisocial behaviour
  • People with such damage tended to show impulsive behaviour and an inability to learn from their mistakes
  • Supports the idea that brain damage may be a causal factor in offending behaviour
• AO3 Neural Explanation: Intervening variables

  • The link between neural differences and APD is complex
  • Other factors may contribute to APD and offending
  • A group of males were studied that scored high on psychopathy
  • They had risk factors such as being raised by a convict or being physically neglected
  • These variables are complex and there may be other variables present
• AO3 Biological Explanation: Socially sensitive

  • The research is socially sensitive as it can harm people for example someone who has the MAOA gene
  • Being labelled as a criminal before you have even committed the crime may lead to committing crime (self fulfilling prophecy)