Biological Explanations

• atavistic form: offenders are genetic throwbacks that do not conform to society through crime
• genetics: dna that produces instructions for physical features of an organism
• neural explanations: activity of the brain such as neurotransmitters, nervous system etc
• what are the three parts to genetic explanations?

  • twin and adoption studies
  • candidate genes
  • diathesis stress model
• what evidence is there for twin studies, as a genetic explanation?

  christiansen - found concordance rates for offender behaviour of 35% for identical twins and 13 % for non-identical - this data indicates that it is not just the behaviour that might be inheritied but the underlying predisposing traits
• what evidence is there for adoption studies, as a genetic explanation?

  crowe - adopted children whos biological mother had a criminal record has a 50% risk of having a criminal record too, but those whose biological mother didnt have a criminal record only had a 5% risk
• what are the two candidate genes for offending behaviour?

  MAOA and CDH13
• what evidence is there for candidate genes, as a genetic explanation?

  tiihonen - a genetic analysis of finnish offenders suggested that these two genes were associated with violent crime
• what is the role of the two candidate genes, as a genetic explanation?

  MAOA: regulates serotonin in the brain and has been linked to aggressive behaviour

  CDH13: linked to substance abuse and ADHD
• outline the diathesis stress model, as a genetic explanation

  a combination of having the candidate gene and a stress trigger (often childhood abuse) is what causes offending behaviour - essentially nature + nurture = crime
• what are the two parts to neural explanations?

  • prefrontal cortex
  • mirror neurons
• outline the prefrontal cortex, including evidence, as a neural explanation

  raine - found that brain imaging studies showed reduced activity in the prefrontal cortex for people with APD, which is the part of the brain which regulates emotional behaviour
• outline mirror neurons, including evidence, as a neural explanation

  keysers - those with APD have a neural switch than can turn mirror neurons on and off and choose when to empathise with people
• who studied atavistic form, as a biological explanation?

  lombroso
• what research did lombros carry out to develop the theory of atavistic form?

  examined facial and cranial features of italian convicts - 40% had atavistic characteristics
• what are example characteristics of atavistic form?

  • big ears
  • facial asymmetry
  • strong prominent jaw
• state and outline the three offender types lombro identified

  born criminals: atavistic form

  insane criminals: mentally ill

  criminaloids: predispose to crime