Biological explanations of offending behaviour

• A historical approach (activist form) to explaining offending behaviour

  Lombroso suggested that offenders were 'genetic throwbacks' that lacked evlutonary development. Their savage and untamed nature ment that these genetic throwbacks would find it difficult to adjust to the demands of civilised society. (Thus, they turn to crime.) hombroso therefore saw criminal behaviour as being determined by genetics and was thus the first biological explaination for offending behaviour.
• what did Lombroso find in his research

  • A narrow, sloping brow
  • A strong prominentjaw
  • high cheekbones
  • Fascial asymmetry
  • Dark skin
• what did Lombroso examine

  From his research examining the facial and cranial features of hundreds of convicts, Lambroso argued that these genetic throwbacks could be identified by atavistic (ancestral) charactersties.
• Lambroso went even further to cate gorise types of criminal in terms of their physical characteristics e.g:

  • Murderers were described as having bloodshot eyes and curly hair
  • Sexual deviants were descri bed as having swollen , fleshly lips and protruding ears
  • fraudsters were described as having thin lips
• Evaluation of the historical approach lactavistform) to explaining offending behavior

  • Emphasis on genetics played an important role in the shift towards scientific theories of offending behaviour
  • There is little supporting evidence for atavistic features in offenders
  • considered a racist theory for offending behaviour
  • Difficult to establish cause and effect between atavistic features and offending behaviour
• what does genetic explainations of offending behaviour suggest?

  It suggests that offenders have inherited genes that predisposed them to commit a crime .

  for example, a genetic analysis of almost 900 offenders has reveiled that many offenders have a low - activity version of the MAOA gene
• The MAOA gene and it's link to criminaIs

  The MAOA gene provides instructions for making the enzyme MAOA. This enzyme breaks down neurotransmitters such as dopamine Ian excitatory neurotransmitter involved in motivation and reward) and serotonin I an inhibitory neurotransmitter involved in impulse control and regulation of emotions).
• What does a low activity version of the MAOA gene result in?

  This would result in less enzymes being produced to break down dopamine and serotonin. This means that offending behaviour has been linked to high levels of dopamine and serotonin.
• What do high levels of serotonin cause?

  This can cause neurons to become . desensitised to the inhibitory effects of serotonin. If neurons are not responding to the inhibitory effects of serotonin , they will continue to fire and arouse the nervous system . This can lead to agitation, restlessness and impulsivity and, inturn, impulsive crimes of agression
• what does high levels of dopamine cause?

  This can cause paranoia which could lead to impulsive acts of aggression as well as reward-seekin behaviour which could lead to crimes such as theft.
• Evaluation of genetic explainations for offending behaviour

  • supporting evidence of twin studies
  • Issues with evidence from twin and adoption studies with reference to the nature - nurture debate
  • A 'criminal gene ' has implications for the law
• summarise neural explainations for offending behaviour

  Neural explainations for offending behaviour sugg sost that offending behaviour is caused by abnormalities in brain structure and/or function. Two areas of the brain that have been implicated in offending behaviour are the prefrontal cortex and the amygdala.
• Evaluation of neural explainations for offending behaviour

  • supporting evidence from brain scanning techniques
  • issues with correlational evidence
  • More casual supporting evidence
  • individual differences questions the generalisability of the theory