Background: Physiological and non-physiological explanations of criminal behaviour.
Key Study: Raine et al. (1997) Brain abnormalities in murderers indicated by positron emission tomography.
Strategy: Biological strategy for preventing criminal behaviour.
Key Study: Raine et al. (1997) Brain abnormalities in murderers indicated by positron emission tomography.
Strategy: Biological strategy for preventing criminal behaviour.
Background: Physiological explanation of Crime
Background: Interactionist Explanation: Diathesis stress model
Background: Non-physiological explanation of Crime
Farringdon and West identified many factors that may determine criminality from a longitudinal study of 411 eight year old boys that they interviewed into adulthood. They found that typical crime risk factors include poor parenting, poverty, history of family criminality, low school attainment and risk taking.
- MAOA gene produces chemical involved in the breakdown of serotonin, dopamine and norepinephrine.
- Brunner et al (1993) studied a large Dutch family where all the males had a mutant form of the MAOA gene. All had borderline retardation and reacted aggressively when angry, fearful or frustrated, suggesting that abnormal MAOA activity is associated with criminality.
Background: Interactionist Explanation: Diathesis stress model
- Genes are the predisposing factor to a criminal behaviour but behaviour will only be shown if there is a precipitating factor from the environment
- Caspi et al (2002) studies 500 male children. Those with low levels of MAOA were more likely to exhibit antisocial behaviour but only if they had been maltreated as children. The interaction between environment and the gene determines aggression.
Background: Non-physiological explanation of Crime
Farringdon and West identified many factors that may determine criminality from a longitudinal study of 411 eight year old boys that they interviewed into adulthood. They found that typical crime risk factors include poor parenting, poverty, history of family criminality, low school attainment and risk taking.
Previous research and context to the study
Aim: To see if violent offenders who commit murder and plead Not Guilty for Reasons of Insanity (NGRI) have localized brain dysfunction.
Research Method/Design
A quasi-experiment. Matched pairs design (age, sex and psychiatric condition).
Participants
Procedure
Ps were injected with an FDG ‘tracer’ and asked to complete a complete a Continuous Performance Task. After 32 minutes of uptake of the tracer, each P was scanned. 2 techniques were used to identify brain regions:
1) Cortical Peel technique (lateral brain areas)
2) Box technique (medial brain areas).
Results
The experimental group had lower levels of glucose metabolism in the lateral and medial pre-frontal cortical regions of the brain. In the subcortical regions the experimental group also had lower glucose metabolism in the corpus callosum and reduced activity in the amygdala (implicated in aggression and emotion regulation).
Conclusions
- Violent offenders have poor brain functioning in comparison to controls but exact brain areas implicated have not been identified.
- Earlier research limited - focuses on aggressive hospital patients.
Aim: To see if violent offenders who commit murder and plead Not Guilty for Reasons of Insanity (NGRI) have localized brain dysfunction.
Research Method/Design
A quasi-experiment. Matched pairs design (age, sex and psychiatric condition).
Participants
- 41 ‘murderers’ (39 male, 2 female), mean age of 34.3 years, NGRI (e.g. history of head injury). Not receiving any psychoactive medication for 2 weeks before the scan.
- 41 controls (39 male, 2 female), mean age of 31.7 years.
Procedure
Ps were injected with an FDG ‘tracer’ and asked to complete a complete a Continuous Performance Task. After 32 minutes of uptake of the tracer, each P was scanned. 2 techniques were used to identify brain regions:
1) Cortical Peel technique (lateral brain areas)
2) Box technique (medial brain areas).
Results
The experimental group had lower levels of glucose metabolism in the lateral and medial pre-frontal cortical regions of the brain. In the subcortical regions the experimental group also had lower glucose metabolism in the corpus callosum and reduced activity in the amygdala (implicated in aggression and emotion regulation).
Conclusions
- Evidence for ‘multi-site deficits’ in murderers pleading NGRI.
- These areas are characterized by reduced glucose metabolism.
- Support for pre-existing biological factors for predisposition to violence.
- Violent behaviour is localized in the brain and may ‘translate’ into criminal behaviour through various pathways including social and cognitive.
Biological Strategy: nutrition for pregnant women
Biological Strategy: nutrition for newborns and children
Biological Strategy: Facial surgery for prisoners before release
- Vitamins free for pregnant women to supplement diet
- Every day, through clinics and doctors
- to ensure babies’ brain develops with good nutrition
- Raine – lower activity in corpus callosum and the amygdala (more aggression and less emotion regulation)
- Casey – lower activity in inferior frontal gyrus in low delayers
Biological Strategy: nutrition for newborns and children
- Omega 3 fish oils free to young children
- Every day, through school and nurseries
- to ensure children’s brain continues to develop with good nutrition
- Raine - fish oil like omega-3 can reduce delinquency, aggression and attention problems after 6 months
Biological Strategy: Facial surgery for prisoners before release
- For long term criminals returning to society, funded by the justice system to prevent recidivism
- To change the face to change the behaviour. Physical appearance can be a self-fulfilling prophecy.
- Dion – halo effect – look good people think you are good, lowers expectations from others Less expectation from others?
- Freedman – criminals showed an increase in cooperation, morale, and optimism, and a decrease in hostility.
Example Section B Answer
Discuss the validity of research into what makes a criminal [15]
A strength of the research into what makes a criminal is its internal validity, this is because much of the research is through highly controlled experiments, which mean that extraneous variables are well controlled. We are shown this through Raine’s study of the brain scans of those pleading not guilty for reasons of insanity to murder / manslaughter. This means it is valid as you cannot fake results of brain scans. However, despite having internal validity, the results could be altered naturally, such as by the stress of going through the noisy MRI scans or PET scans which inject the recipients with radioactive tracers.
A weakness of the research into what makes a criminal is low ecological validity of the results, especially with the use of brain scans (e.g. Raine and Casey) or interviews (e.g. Hancock), this is due to brain scans and interviews not showing what they do during a criminal act. We can use Casey’s study to show this when she only used brain scans in the second half of her experiment. This means there is low ecological validity because brains scans were not used during the crime, so the results cannot prove cause and effect or even correlation. However, it is impossible to scan a criminal’s brain during their criminal act, so the results are always going to lack ecological validity.
Another weakness of the research into what makes a criminal is that there is low population validity of the samples used. The sample size and origin may lack generalisability to the criminals worldwide. For example, with research into physiological (genetic) explanations such as that by Brunner, a single Dutch family were used. It is an ethnocentric study as only Dutch people were used. It was also androcentric because only men were used from the Dutch family, yet not only men commit crime as criminal acts happens everywhere. However, it is not possible to get a sample from everywhere and as men are much more likely to commit or be convicted of crime, it is reasonable that samples for this research are androcentric.
A strength of the research into what makes a criminal is its internal validity, this is because much of the research is through highly controlled experiments, which mean that extraneous variables are well controlled. We are shown this through Raine’s study of the brain scans of those pleading not guilty for reasons of insanity to murder / manslaughter. This means it is valid as you cannot fake results of brain scans. However, despite having internal validity, the results could be altered naturally, such as by the stress of going through the noisy MRI scans or PET scans which inject the recipients with radioactive tracers.
A weakness of the research into what makes a criminal is low ecological validity of the results, especially with the use of brain scans (e.g. Raine and Casey) or interviews (e.g. Hancock), this is due to brain scans and interviews not showing what they do during a criminal act. We can use Casey’s study to show this when she only used brain scans in the second half of her experiment. This means there is low ecological validity because brains scans were not used during the crime, so the results cannot prove cause and effect or even correlation. However, it is impossible to scan a criminal’s brain during their criminal act, so the results are always going to lack ecological validity.
Another weakness of the research into what makes a criminal is that there is low population validity of the samples used. The sample size and origin may lack generalisability to the criminals worldwide. For example, with research into physiological (genetic) explanations such as that by Brunner, a single Dutch family were used. It is an ethnocentric study as only Dutch people were used. It was also androcentric because only men were used from the Dutch family, yet not only men commit crime as criminal acts happens everywhere. However, it is not possible to get a sample from everywhere and as men are much more likely to commit or be convicted of crime, it is reasonable that samples for this research are androcentric.