Abstract
Previous studies have suggested that offenders have lowered verbal intelligence compared to their performance intelligence. This phenomenon has been linked traditionally to childhood risk factors (e.g. deficient education, abuse and neglect). Substantial discrepancies between performance intelligence quotients (PIQ) and verbal intelligence quotients (VIQ), however, might also point to neurobiological impairments which may be associated with specific types of criminal behaviour. From the files of 133 male hospitalized offenders, PIQ, VIQ, full scale IQ (FSIQ) scores and Psychopathy Checklist-Revised (PCL-R) scores were derived, along with information about their criminal histories. PIQ over VIQ discrepancies were most pronounced in sexual offenders, particularly in those who had committed sexual crimes against adult victims. Furthermore, PIQ as well as PIQ higher than VIQ discrepancies correlated modestly, but significantly, with PCL-R scores. The results suggest that lower verbal compared to visual and spatial abilities may be connected specifically to egocentric and narcissistic personality traits which, in turn, may be involved in raising the risk of sexual offending.
