Psychopathy is characterized by diverse indicators. Clinical accounts have emphasized 3 distinct facets: interpersonal, affective, and behavioral. Research using the Psychopathy Checklist--Revised (PCL-R), however, has emphasized a 2-factor model. A review of the literature on the PCL-R and related measures of psychopathy, together with confirmatory factor analysis of PCL-R data from North American participants, indicates that the 2-factor model cannot be sustained. A 3-factor hierarchical model was developed in which a coherent superordinate factor, Psychopathy, is underpinned by 3 factors: Arrogant and Deceitful Interpersonal Style, Deficient Affective Experience, and Impulsive and Irresponsible Behavioral Style. The model was cross-validated on North American and Scottish PCL-R data, Psychopathy Screening Version data, and data derived from the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) antisocial personality disorder field trial.

The development of the Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 2003) has fueled intense clinical interest in the construct of psychopathy. Unfortunately, a side effect of this interest has been conceptual confusion and, in particular, the conflating of measures with constructs. Indeed, the field is in danger of equating the PCL-R with the theoretical construct of psychopathy. A key point in the debate is whether criminal behavior is a central component, or mere downstream correlate, of psychopathy. In this article, the authors present conceptual directions for resolving this debate. First, factor analysis of PCL-R items in a theoretical vacuum cannot reveal the essence of psychopathy. Second, a myth about the PCL-R and its relation to violence must be examined to avoid the view that psychopathy is merely a violent variant of antisocial personality disorder. Third, a formal, iterative process between theory development and empirical validation must be adopted. Fundamentally, constructs and measures must be recognized as separate entities, and neither reified. Applying such principles to the current state of the field, the authors believe the evidence favors viewing criminal behavior as a correlate, not a component, of psychopathy.

Psychopathic personality disorder (PPD) has important clinical and forensic implications. But much more effort has been devoted to assessing or diagnosing PPD than to explicating or defining it. In the first part of this paper, we describe the development of a conceptual model or "concept map" of PPD. Based on a systematic review of descriptions of PPD in the clinical and research literature, as well as consultation with subject matter experts, we identified key features of the disorder and translated them into 33 symptoms, presented as natural language (i.e., non-technical) trait descriptive adjectives or adjectival phrases. Each symptom in turn was defined by three synonymous adjectives or adjectival phrases. The 33 symptoms were grouped rationally to reflect six domains of personality functioning. In the second part of the paper, we discuss research completed and in progress intended to validate the CAPP conceptual model.

Differences in the prevalence and presentation of psychopathic personality disorder between North America and Scotland were evaluated. R. D. Hare's (1991) Psychopathy Checklist-Revised ratings obtained from a sample of 2,067 North American male prisoners and forensic patients were compared with ratings obtained from 246 Scottish male prisoners. Item response theory methods were used to examine differences in the performance of items and to equate the scale across settings. The items had equal relevance to the description of psychopathic personality disorder in both settings; however, the Scottish prisoners had to have higher levels of the underlying latent trait before certain characteristics became apparent. The prevalence of the disorder appears to be lower in Scotland. Explanations for the observed differences in terms of enculturation, socialization, and migration are explored.

The Psychopathy Checklist-Revised (PCL-R) is an important measure in both applied and research settings. Evidence for its validity is mostly derived from male Caucasian participants. PCL-R ratings of 359 Caucasian and 356 African American participants were compared using confirmatory factor analysis (CFA) and item response theory (lRn analyses. Previous research has indicated that 13 items of the PCL-R can be described by a 3-factor hierarchical modeL This model was replicated in this sample. No cross-group difference in factor structure could be found using CFA; the structure of psychopathy is the same in both groups. IRT methods indicated significant but small differences in the performance of 5 of the 20 PCL-R items. No significant differential test functioning was found, indicating that the item differences canceled each other out. It is concluded that the PCL-R can be used, in an unbiased way, with African American participants.