Psychopathy and dangerousness: comparison, integration and extension of two psychopathic typologies.

Previous research has failed to relate psychopathy to an increased risk for violence, but several proposed psychopathic typologies have suggested the possibility of isolating more dangerous subtypes. One typology, based upon psychopathy and intelligence, has identified the low IQ psychopath as excessively violent judged by his history of violent crime. A second typology involving psychopathy and social withdrawal predicts greater dangerousness for both the outgoing and the withdrawn psychopath depending upon circumstance. The present study confirmed the dangerousness of the low IQ and withdrawn psychopaths in their prison behaviour and the low IQ psychopath on parole. The attempt to develop a more homogeneous type of dangerous psychopath by increasing the number of defining attributes was successful. The highest prison and parole dangerousness scores in the prisoner sample were obtained by those who shared four attributes. They were (1) psychopaths, who (2) had low IQs, (3) were socially withdrawn, and (4) had a history of prior violent crime.