The intention of this study was to examine the relationship between the right and left hemispheres of the brain and criminal behaviour. It was predicted that prisoners scoring higher on the Verbal scale than the Performance scale of the WAIS-R would tend to commit more analytical thought-out
crimes. Those scoring higher on the Performance scale may be more impulsive type criminals and tend to commit crimes less thought out. A total of 51 inmates were tested with the WAIS-R. Inmates who scored lower on the Verbal scale than the Performance scale tended to be more impulsive. Due
to the overlap in crimes committed by both types of criminals, it was recommended that future research in this area may include a third category of both impulsive-non-impulsive along with the separation of the two categories.