methodology

• point :)

  PET scans were used as a research method
• evidence :)

  Raine injected participants with a FDG tracer, and then used a PET scan to take 10mm horizontal slices of images of the brain. He found some significant differences in brain activity between the NGRI and control group.
• explain :)

  PET is a highly reliable brain imaging technique that produces objective and replicable results, and can be tested and re-tested.
• link :)

  with such a highly scientific method being used, Raine's research has scientific status and can be trusted over less scientific methods where results cannot be quantified.
• point :(

  with the method used, it is not possible to fully state a cause-and-effect relationship
• explain :(

  as Raine emphasised, the findings don't show that violence is determined by biology alone, as other factors, such as psychological, can influence violence.
• example :(

  some of the NGRI participants may have developed their brain dysfunction as an effect of the violence, due to the stress of the imprisonment, and arrest, etc.
• link :(

  therefore, although the methodology does go some way at hinting at a relationship between areas of the brain and aggression, further research with NGRI participants would need to be carried out.