biological explanations

• genetic explanation:

  candidate genes: criminality could be the result of faulty candidate genes - faulty MAOA will result in an imbalanced level of serotonin - higher

  • high serotonin = high aggression, more likely to commit domestic and violent crimes
• Brunner: studied 28 males all from the same family who had a history of violent and impulsive behavior - found that they all had a faulty MAOA gene
• Tiihonen (2015): looked at 800 Finnish offenders and discovered that the MAOA and CDH-13 were associated with violent crimes

  • CDH-13 is linked to susbtance abuse and ADHD = explains impulsive and drug-related crime
• Christiansen (1977): studied over 3,500 twin pairs in Denmark and found the concordance rates for offenders behavior of 35% identical MZ twin males and 13% non-identical DZ
• neural explanation: focuses on the differences and abnormalities in the brains of criminals

  • pre-frontal cortex: responsible for emotion and moral behavior, the more activity means you are using logical and rational thinking
• Raine (2000): found a 11% reduction in volume of grey matter in the PFC with individual who have APD, then conducted a meta-analysis of 71 brain imaging studies showing murders and found they had a reduced functioning in the PFC
• mirror neurons: allow empathy, can switch their neuron on and off to show their empathy when they aren't committing crime
• evaluation:

  strength

  • g - evidence from MZ/DZ twin studies who looked at genetic factors
  • supporting studies from Brunner, Tiihonen and Christiansen

  weakness:

  • g - based on animal studies, may not tell us about human offending
  • n - may develop it after the crime, may not always be innate
  • offending may be better explained through SLT and reward systems