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Background Hervey Cleckley’s description of psychopathic personality detailed in his book, The Mask of Sanity (1941/1976), has strongly influenced the last seven decades of empirical research on psychopathy. Nevertheless, there has been a long ongoing discussion of what should be included in the conceptualization of the psychopathy construct. While Cleckley emphasized the emotional and interpersonal deficits, others also included antisocial behavior as a defining feature. While a tremendous amount of research has been conducted on psychopathy, there are considerable mixed and sometimes contradictory findings reported in the literature. The overall aims of this thesis were to explore possible discrepancies within the modern psychopathy construct, and to see if possible underlying heterogeneities and/or if the use of different psychopathy assessment instruments might explain some of the previous mixed findings. There exist several instruments designed to assess psychopathic personality. This multitude of instruments differs in assessment methodology (i.e. self-report, clinical assessment), as well as on the theoretical focus. In the first paper, we explored the inter-correlations between three psychopathy assessment instruments (The Psychopathy Checklist – Revised [PCL-R], The Comprehensive Assessment of Psychopathic Personality – Institutional Rating Scale [CAPP-IRS], and The Self- Report Psychopathy Scale – III [SRP-III]) to evaluate if the instruments conceptually assess the same psychopathic construct. In the second and the third paper we investigated the relationship between the psychopathy construct and cognitive, emotional and physiological external correlates. The second papers investigated the relationship between psychopathy and Theory of Mind capabilities. The inclusion of both self-report (SRP-III) and a clinical assessment (PCL-R) of psychopathy also allowed us to investigate whether methodological differences affected the results, and hence explain some of the previous mixed findings in the field. Several previous studies have shown associations between psychopathy and the experience of negative affectivity. We wanted to further examine this relationship, and to better understand how potential underlying mechanisms affect the relationship, we also controlled for other known biological and cognitive correlates of negative affectivity. Methods Ninety-two male prison inmates at Bergen prison, Norway participated in the study. Psychopathic personality was assessed with three different assessment instruments (PCL-R, CAPP-IRS, and SRP-III). Computer based experimental tasked was used to measure Theory of Mind capabilities (emotional recognition; Reading the Mind in the Eyes Test [RMET]) and executive functioning (Tower of London). Heart rate variability (HRV) was included as an index of autonomic selfregulation. The experience of negative affectivity (general psychological distress, depression, anxiety, and aggression) was assessed through self-reports. Results The correlational analysis in paper 1 showed a high degree of inter-correlations between the instruments, but substantial divergence was also found. CAPP-IRS and PCL-R showed high inter-correlations and, hence, seem to tap into the same underlying construct. However, CAPP-IRS seems to have a higher affective focus in all its domains. Our finding of lower correlation between the SRP-III (selfreport) and the other two clinical tools may suggest a limitation in the instrument to uncover the full range of the psychopathic construct. Especially the interpersonal and affective segments seemed to be missed. In paper 2, we found some discrepancy in the relationship between psychopathic traits and emotional recognition connected to psychopathy assessment methodology. For the self-report (SRP-III) there was an overall negative association between mental state discrimination and psychopathy, while for the clinical instrument (PCL-R), the results were more mixed. For Factor 1 psychopathic traits (interpersonal and affective traits), we found a positive association with discrimination of neutral mental states, but not for the positive or negative mental states. Factor 2 traits (impulsive and antisocial lifestyle) were found to be negatively associated with discrimination of mental states. In paper 3, the initial correlation analyses revealed significant associations between psychopathy and negative affectivity. However, in subsequent regression analyses, when controlling for underlying self-regulatory mechanisms, this association between psychopathy (Factor 1 and Factor 2) and negative affectivity measured through Symptom Check-List Revised (SCL-90-R) and Hospital Anxiety and Depression Scale (HADS) disappeared. PCL-R Factor 2 remained the strongest significant predictor of aggression. Conclusion Overall, the results from the three papers challenge a view of psychopathy as an etiologically homogenous construct. All three papers find empirical support for an inherent heterogeneity within what traditionally is called "psychopathy”, and this heterogeneity seems to be especially salient in regard to affective and emotional processing. The PCL-R as a single well-validated measure of psychopathy has over the years come to dominate the scientific field of psychopathy. Our results add to a growing body of research showing both dimensionality and heterogeneity related to the psychopathy construct, and especially related to PCL-R psychopathy. The finding that PCL-R factors relate differently to negative affectivity, aggression and Theory of Mind capabilities, might indicate that the underlying factors of psychopathy represent somewhat different underlying concepts, rather than a unitary construct.
