Social explanation: Families:

• Focus on influence of other people such as parents on criminal behaviour
  
  

• Farrington (2006) -> criminal behaviour influenced by family life such as parental criminality/absence
• 411 males from working class inner city London first studied at 8 yrs until 48 yrs
• Asked about living circumstances/leisure activities
• Also tested at school for attainment and intelligence
• Parent interviews conducted with psychiatric social workers -> incomes, attitudes to discipline, separations from son
• 8-10yrs risk factors for later offending measures of family criminality, loss of mother, low school attainment, poverty, poor parenting

Social explanation: Norms:

• Sutherland 91947) proposed differential association theory -> criminal behaviour learned through interaction with others
• Frequency and intensity of interaction with people with pro-criminal attitudes important for Sutherland
• Akers et al (1979) -> 68% variance in marijuana use of 2500 American adolescents could be association and reinforcement of peers

Cognitive explanations:

• Focus on level of moral development and lack of moral reasoning shown by criminals
• Kohlberg (1984) not applied to criminal behaviour but can show how lack of moral reasoning explains crime
• Behaviour governed by whether outcome is good/ bad for individual, not societal views
• Palmer and Hollin (1998) -> compared moral reasoning of male delinquents and male/female non-delinquents
• Delinquents have less mature moral reasoning

Design:

• Quasi experiment -> IV = murderer or not, DV = activity in specific brain regions
• Matched participants

Sample:

• 41 murderers, 39 male, 2 female, mean age 34.3 years
• Charged with murder or manslaughter and pleaded not guilty by reason of insanity (NGRI) or incompetence to stand trial
• Schizophrenia (6), brain injury (23), psychoactive drug abuse (3), affective disorder (2), epilepsy (2), hyperactivity or learning disability (3), personality disorder (2)
• Control with no mental illness matched by age and sex
• Schizophrenia matched with schizophrenia
• Medication free two weeks prior to study

• Consent forms approved by Human Subjects Committee of the University of California
• Ps required to work for 32 minutes on a continuous performance task (CPT) based on target recognition
• CPT designed to work areas of brain that were to be studied to monitor level of function
• Ps able to practise CPT 10 mins before glucose tracer (fluorodeoxyglucose or FDG) injected so novelty of talk not labelled by FDG
• 32 mins after injection, PET scan took 10 slices at 10mm intervals of (sub)cortial regions of the brain

Materials:

• Thermoplastic head holder modelled to each p
• CPT involved ps looking for targets and pressing button when found
• PET scan to study active brain

Brain differences:

• Murderers have reduced activity in prefrontal cortex, left angular gyrus, corpus callosum
• Reduced activity in amygdala, thalamus, hippocampus in left hemisphere
• High activity in cerebellum, amygdala, thalamus, hippocampus in right hemisphere

Behavioural performance on CPT:

• No difference

Other differences not previously matched:

• Handedness -> 6 murderers were LH, less amygdala symmetry, higher medial prefrontal in RH
• Ethnicity -> 14 non-white murderers, no difference compared to white
• Head injury -> no difference

• Murderers pleading NGRI function differently to normal
• Neural processes underlying violence are complex and cannot be reduced to single brain mechanism
• Social, physiological, cultural, situational factors play role in predisposition to violence
• Brain dysfunction may be effect of violence
• Results relate only to criminal behaviour
• Results show link between brain dysfunction and predisposition towards violence in NGRI group

• Diet has important bearing on aggression and criminal behaviour (Zaalberg et al 2010)
• Low omega-3 limits regulation of limbic system

Example of a nutritional supplement regime for prisoners:

• Nutritional supplements contain 1 vitamin/mineral, 4 fatty acid
• Everyday, pack labelled with prisoner's name, cell and prison number, given at lunchtime
• Omega-3 to be taken 4 times a day and vit/min at lunch
• Supplement dosages match recommended intake
• Everyday for 1 month
• Consumed under watch of guards to ensure compliance

Freewill:

• Criminal justice system based on belief that all and every behaviour is a choice
• People born with low resting heart rate, not everyone will be a criminal

Hard determinism:

• Any biological explanation/physiological -> criminal behaviour outside of individual's control

Soft determinism:

• Living in poverty/disadvantaged areas, doesn't mean everyone will, some element of freewill

Reductionist:

• All biological are reductionist
• Fail to take into account social context that criminal behaviour takes place in
• Sutherland (1947) -> others influence criminal behaviour

Holistic:

• Farrington (2006) -> different types of reasons that become causes for criminal behaviour

Individual:

• Mix of nature/nurture -> upbringing/biological factors/personality

Situational:

• Given opportunity to commit crime, currently being in poverty, going through break up, etc

Interactionist:

• Characteristics that make us likely to behave in criminal way, only will do so if opportunity arises

Useful:

• Lots of interventions can be placed to prevent crime
• If biological, crime can be prevented
• Social factors -> more police (e.g)/more investment
• Give appropriate defence for certain situations -> rehabilitation

Not useful:

• Not realistic to solve all these behaviours

Ethical:

• Strict because of radioactive substance used in PET scan -> informed consent

Not ethical:

• Harm could have been caused to experimental group -> if found out about brain difference -> psychological harm/distress

Sensitive:

• Those who break the law choose to do so, if causes of crime are out of person's control -> undermines criminal justice system

Not sensitive:

• Could lead to changes in system

Science:

• PET scans are objective

Not scientific:

• Can't establish cause and effect
• Small sample of caught murderers -> bias -> not valid

Valid:

• Objectivity of PET scans

Not valid:

• Can't generalise
• Low in population validity

Ethnocentric:

• Criminal behaviour is culturally relative -> changes often and isn't fixed -> Farrington (causes for criminal behaviour based on UK nuclear family)

Not ethnocentric:

• Species specific -> no cultural bias implied

Reliable:

• Standardised machines for scans
• Replicable with non-murdering criminals

Bias:

• Only murderers, NGRI

No bias:

• Physiological difference -> species specific