crime 1

• Criminal behaviour


  The intentional commission of an act usually deemed socially harmful or dangerous and specifically defined, prohibited, and punishable under criminal law
• Family history studies - Criminal behaviour has a tendency to run in families
• Even if we accept that the higher rate of criminality in the sons of criminal fathers is attributable to genetics, it is still necessary to explain why 60% of them did not go on to commit crimes and why 13% of the sons of non- criminal fathers did (Ainsworth, 2000).
• Concordance rates


  When you look at the degree of pairs of twins with a matched attribute. In this case, this is whether or not each twin has engaged in criminal behavior.
• High concordance rate


  Indicates high degree of twins share a specific attribute
• Low concordance rate


  Indicates low degree of twins share a specific attribute
• In family and twin studies, the participants live together so it's impossible to disentangle the influence of nature or nurture.
• Adoption studies


  Similarities between biological parents and their children suggest that genes are important whereas similarities between adoptive patents and their children suggest that the environment is important.
• Genes have an influence, environment has an influence but the combination of genes AND environment seem most influential.
• MAOA-L - Warrior gene


  Responsible for the enzyme MAOA. The function of this enzyme is to help breakdown excess serotonin in the brain. High levels of serotonin have been associated with aggressive behaviour.
• Statistically, men commit significantly more crime.
• The limbic system (amygdala, hippocampus and thalamus) are another set of structures which may play a role in abnormal emotional responses, hence leading to criminal behaviour.
• Amygdala


  Responsible for feelings of fear. People with exaggerated amygdala reactivity show impulsive aggression whereas people with reduced volume are cold and calculating.
• Hippocampus


  When damaged, associated with impulsive activity.
• Thalamus


  Damage to the thalamus is thought to be linked to combativeness (aggression).
• SLT claims that behaviour is the result of the social environment in which a child grows up. The suggestion is that children acquire criminal behaviour through processes of reinforcement and imitation of criminal "models". Behaviour that is rewarded or reinforced is likely to be repeated and learned. For example, gaining material goods by stealing.
• By the age of 32: 37% had committed a criminal offence (31% national average), Peak offence rate was at 17. Offending was very much concentrated in families. The worst offenders seem to come from large-sized multi-problem families. (SLT?!)
• Social Learning Theory


  Theory that criminal behaviour is learned through interaction with others
• Farrington and West (1996) conducted a longitudinal study (interviews and tests) on 411 London boys born mostly in 1953, aged 8,10,14,16,18,21
• Procedureof Farrington and West


  1. Interviews and tests on the boys

  2. Interviews with the boys' mothers

  3. Questionnaires completed by teachers

  4. Peers provided evidence

  5. Criminal records obtained
• Farrington and West

  By the age of 32, 37% of the boys had committed a criminal offence
• The worst offenders seem to come from large-sized multi-problem families
• Predictors of crime at 8-10 years

  • Family criminality
  • Family poverty (including low family income, large family size and poor housing)
  • Low intelligence and poor school attainment, poor concentration
  • Poor parental supervision, parental conflict and separation from parents
• Differential Association Theory proposes that we learn criminal behaviour through interaction with others
• Akers (1979) found that 68% of marijuana use of 2,500 American adolescents can be explained in terms of differential association/ reinforcement from peers
• Becker's Rational Choice Theory states that criminal behaviour is a choice, as people intentionally choose to partake in criminal behaviour if they think it will be more rewarding and less costly for them than non-criminal behaviour
• Omega 3 supplements may reduce aggression and criminal behaviour by enhancing brain structure and function
• Providing a balanced, nutritious diet, physical exercise and cognitive stimulation to children can reduce bad behaviour by improving their ability to focus attention
• The health and nutrition of pregnant women could be an effective biosocial intervention to reduce antisocial behaviour in children
• A 15 year follow up study showed a 53% reduction in arrests and a 63% reduction of convictions when low class women received home visits from nurses, advice on reducing smoking/alcohol and advice on how to meet child's needs
• Raine(1997) Background


  Violent offenders have poor brain functioning in comparison to controls but implicated brain areas have not been identified.
• Raine (1997) Aim


  To study brain activity in murderers using PET scans to find out if there were differences in areas thought to be involved in violent behaviours
• Raine(1997) sample


  41 murders, mean age of 34.3

  all charged with manslaughter or murder

  all pleaded not guilty through reasons of insanity

  no p's took medication for 2 weeks prior
• Raine(1997) Procedure 1.


  Brain scanned during CPT as it increases activity in areas of interest.

  Injected with fluorodeoxygen glucose so task wouldn't appear as an event.

  CPT lasted for 32 mins. 10 horizontal "slices" od 10mm intervals taken.
• Raine(1997) Procedre 2.

  1. Cortical Peel Technique- lateral brain areas
  2. Box Techniques- medial brain areas eg frontal gyrus
• Raine(1997) Findings


  Murderers had significantly less activity in lateral/medial/parietal prefrontal cortical areas of the brain/ corpus callosum

  Suggests murders inability to grasp consequences of an action.
• Raine(1997) Findings


  Murderers had asymmetrical activation in areas of the limbic system including the amygdala and greater activation on the right in the temporal lobe, hippocampus and the thalamus.
• Raine(1997) Conclusions


  1. Evidence for areas of abnormal activity being associated with aggressive behaviour eg lack of fear=amygdala, impulsiveness=pre-frontal cortex.
  2. affects on areas associated with learning could lower IQ leading to unemployment and higher risks of criminality