3.3.1 - Raine et al - Classic Study (1997)

A

Investigate murderers pleading NGRI show brain abnormalities

What was the method/ sample?

• PET scans to measure brain activity

• 41 murders vs 41 control

• Completed a continuous performance task during the scan

R:

• Reduced activity in prefrontal cortex - linked to poor impulse control

• Increased activity in amygdala - linked to aggression and emotion

• Abnormal activity in corpus callosum

C

• Suggests biological basis for violent behaviour

• Brain dysfunction may contribute to aggression and lack of control

Strengths?

Strengths:

• Controlled comparison group - matched on age, gender, reducing extraneous variables - differences are more likely linked - improves internal validity

• Scientific/ objective - PET scans quantitative and objective data about brain activity - reduces researcher bias - incr4eases reliability - procedure is replicable and standardised

Weaknesses?

• Quasi experiment - not a true experiment - cant say brain abnormalities cause violent behaviour - possibility violent lifestyle changed the brain

• Lack generalisability - participants were only murders pleading NGRI very specific - cant be generalisable for the whole population