Classic Study Biological Raine Flashcards
Methodology
Quasi experiment with a matched pairs design
IV and DV
IV = NGRI or not
DV = brain differences
Participants
41 murderers -39 men and 2 women
Mean age was 34.3 years
All charged with murder or manslaughter
All pleaded NGRI
Control group
Matching each murderer to a normal individual who was same sex and age
Procedures
Opportunity sampling and PET scan used to study the brain
All ppt injected with tracer and had to do a CPT to activate the target areas of the brain so they could see how different parts functioned
Findings - reduced activity in the brain
Reduced activity in those pleading NGRI in areas previously linked to violence - left side of the brain
Prefrontal cortex, amygdala and hippocampus
Findings increased and no activity in the brain
Increased activity in the brain in those pleading NGRI in areas not linked to violence Prefrontal cortex
The right hemisphere
No difference between those pleading NGRI in areas not linked to violence Prefrontal cortex
Midbrain
Performance on CPT
Both groups performed similarly on CPT so brain differences were not related to task performance
Ethnicity
14 murders were non white but there was no difference in brain activity between them and white murderers
Head injuries
23 murderers had had a brain injury but there was no difference in brain activity between them and those who didn’t have a brain injury
Conclusions
Results do not show that violent behaviour is determined by biology but psychological, cultural and social factors play an important role in violent behaviour
Quasi experiment evaluation
Conclusions are not justified as their finding do not show that violent behaviour is determined by biology alone
Raine suggests that psychological cultural and social factors may influence violent behaviour as well
PET scan evaluation
PET scans allow researchers to study detailed parts of the brain while the brain is in action. This allowed Raine to see how the brains of individuals differed in how they processed information
Sample evaluation
The finding do not show that all murderers have these brain dysfunctions. Raines conclusions are restricted to a very particular group of people
ethical issues
Valid consent - those pleading NGRI were not mentally competent to give their valid consent to this research
CPT may have been difficult causes their self esteem to be lower than when they started meaning they have psychological harm
Right to withdraw ethics
The ppts may not have fully understood that they had the right to withdraw from the research as they were prisoners
