bio

• biological explanations - atavistic form -

  • Lombroso studied the facial and cranial features of - 389 dead convicts and 3839 living convicts 
  • Concluded that there was an atavistic form - physical markers of head and face that make criminals different from the rest of us 
• features of an offender (according to lombrosso) narrow sloping strong brow , strong jaw, high cheekbones, facial asymmetry. Extra toes, nipples or fingers. Left handed.
• • Lombroso also came up with characteristics for different offender types:
  • Murderers - long ears, bloodshot eyes, curly hair
  • Sexual criminals - glinting eyes, swollen fleshy lips 
  • Fraudsters - thin and reedy lips
• Genetic explanations of criminal behaviour:

  • 2015 Finnish study with 800 violent criminals - found 2 genes linked to violent behaviour:
  • MAOA gene - responsible for creating an enzyme which is responsible for the breakdown of serotonin and dopamine once they're no longer needed - if left to build up in the brain, they can be linked to impulsive behaviours 
  • CDH-13 gene - important for forming neural connections in the brain - mutations in this gene are linked to substance abuse, major depression and ADHD
  • People with these genes are 13X more likely to commit a crime
• Supportive evidence of genetic explanation

  • Christiansen - 3500 pairs of twins in Denmark - investigating concordance rates of offending behaviour - 35% for MZ and 13% for DZ
  • Concordance rates suggest a possible genetic element - increases external validity of explanation
• supportive evidence of genetic explanation:

  Crowe - adopted children whose biological mother had a criminal record - found a 50% chance of having criminal record by 18 - Suggests a genetic basis as these children didn't have criminal environments but still committed crimes - adds external validity 
• Neural explanations of criminal behaviour:

  • There is evidence to suggest there may be neural differences in the brains of offenders and non-offenders 
  • Research involves individuals with antisocial personality disorder (often diagnosed in offenders) - involves impulsivity, dishonesty, lack of remorse
• neural explanations -

  Abnormalities in the prefrontal cortex 

  • Prefrontal cortex helps with self-regulation, impulse control, decision making
  • Raine et al:
  • Procedure - volume of grey and white matter in the brain measured in 21 people with APD and 21 without - using mri. Also measured response to stressful situation 
  • Findings - reduced amount of grey matter (11%) was found in the prefrontal area for the APD group. They also showed a reduced autonomic response in people with APD when in a stressful situation
• limitation of Raine et al research - small sample, sample is on people with APD not criminals - only shows a link between APD and neural issues not a link with criminal behaviour
• supportive research for neural explanation

  • Burns et al:
  • Case study of a man displaying paedophilic and violent behaviours 
  • Brain scan showed a tumour on his prefrontal cortex 
  • Tumour was removed and violent paedophilic behaviours stopped 
  • Suggesting that…. Criminal behaviour is due to neural irregularities, increasing the validity of the neural explanation of criminal behaviour 
• opposing evidence of atavistic form - Goring - compared a[pearance of 3000 offenders and 3000 non-offenders and concludes that there was no evidence that offenders are a distinct group of people with unusual characteristics