genetic and neural

• genetic explanations - 


  would-be offenders inherit a gene or combinations of genes that predispose them to commit crime
• genetic explanations: twin and adoption studies -

  • Christiansen (1977) studied over 3500 twin pairs in Denmark - found concordance rates for offender behaviour of 35% for identical twin (MZ) males + 13% for non-identical twin (DZ) males - slightly lower rates for females - included all twins born between 1880-1910
  • Crowe (1972) found adopted children whose biological mother had a criminal record had a 50% risk of having a criminal record by the age of 18 - adopted children whose biological mother didn't have a criminal record only has a 5% risk
• genetic explanations: candidate genes -

  • Tiihonen et al (2015) genetic analysis of 800 Finnish offenders - 2 genes (MAOA and CDH13) may be associated with violent crime
  • MAOA gene - regulates serotonin in the brain - linked to aggressive behaviour
  • CDH13 gene - linked to substance abuse and ADHD
  • analysis found that about 5-10% of all severe violent crime in Finland is attributable to the MAOA and CDH13 genotypes
• genetic explanations: diathesis-stress model -

  • if genetics have an influence on offending its likely that this is at least partly moderated by the effects of the environment
  • tendency towards offending behaviour may come about through the combination of genetic predisposition and biological or psychological trigger
  • eg being raised in a dysfunctional environment or having criminal role models
• neural explanations -

  • evidence suggests there may be neural differences in brains of offenders and non-offenders
  • much evidence in this area has involved individuals diagnosed with antisocial personality disorder (psychopathy) - associated with reduced emotional responses, lack of empathy for feelings of others and a condition that characterises many convicted offenders
• neural explanations: prefrontal cortex -

  • Raine - conducted studies of the APD brain - reported several dozen brain-imaging studies demonstrating that these individuals have reduced activity in prefrontal cortex - part of brain which regulates emotional behaviour
  • Raine et al (2000) found an 11% reduction in volume of grey matter in the prefrontal cortex of people with APD compared to controls
• neural explanations: mirror neurons -

  • research suggests that offenders with ADP can experience empathy but do so more sporadically
  • Keyseres (2011) - found only when offenders were asked to empathise did their empathy reaction (controlled by mirror neurons) activate
  • suggests ADP individuals are not totally without empathy - have neural 'switch' that can be turned off and off unlike 'normal' brain which has empathy permanently on