Previous studies have reported numerous correlations between psychopathy and various personality traits, behavioural tendencies or clinical characteristics. The present study examined in greater depth the relationships between the components of psychopathy as measured by the Psychopathy Checklist—Revised (PCL-R) and intelligence as well as impulsivity. A total of ninety male violent offenders were recruited from a prison and a forensic–psychiatric hospital in Germany. All of the subjects were assessed using the PCL-R, the Barratt Impulsiveness Scale (BIS-11), and a short version of the German Wechsler Adult Intelligence Scale (WIP). As expected, a canonical correlation analysis showed a negative association between spatial intelligence and the Factor 2 subtotal on the PCL-R (reckless lifestyle/antisociality). In addition, our results agreed with the assumption of an association between impulsivity and the subtotal for PCL-R Factor 2. The positive relationship between verbal intelligence and the subtotal for Factor 1 of the PCL-R (insincere, manipulative conduct/affective deficits) vanished after controlling for educational level. The results indicate that there is a relationship between the spatial components of intelligence and the concept of psychopathy as described by Hare. This result supports the spatial impairment aetiological model of antisocial behaviour.
Psychopathy is a trait that partially overlaps with dissocial personality disorder ( World Health Organization, 2004) and antisocial personality disorder ( American Psychiatric Association, 2000). More specifically, psychopathy may represent an extreme form of antisocial personality disorder ( Coid & Ullrich, 2010). The distinctive features of psychopaths are egocentricity, deceitfulness, shallow emotions, lack of empathy, stimulation seeking, impulsivity, and a tendency to ignore or violate social conventions and rules ( Hare, 2003). In comparison with antisocial or dissocial personality disorder, psychopathy focuses more on interpersonal and affective characteristics in a manner consistent with impulsive, antisocial tendencies ( Hare, 2003 and Hare and Neumann, 2008). The most common assessment instrument for psychopathy is the Psychopathy Checklist—Revised (PCL-R) by Hare (2003). The PCL-R can be divided into four dimensions: Interpersonal, Affective, Lifestyle, and Antisocial ( Hare, 2003 and Hare and Neumann, 2008). These four dimensions reflect two factors conceptualised by Hare (2003). Factor 1 is described as a set of characteristics, such as manipulative behaviour, egocentricity, lack of remorse and callousness; this factor integrates the Interpersonal and Affective dimension. Factor 2 identifies chronically unstable and antisocial lifestyles, which are correlated with antisocial personality traits, criminal behaviour, and substance abuse ( Hare, Hart, & Harpur, 1991).
We found a negative relationship between spatial intelligence and Factor 2 scores on the PCL-R as well as a tentative positive link between verbal intelligence and Factor 1 scores on the PCL-R. These results support Raine et al.'s (2002) hypothesis that spatial impairments would play a more decisive aetiological role than verbal deficits in the development of antisocial and psychopathic tendencies. Impulsivity was most strongly correlated with Factor 2, which is consistent with previous findings (Verona et al., 2001 and Snowden and Gray, 2011).
