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.

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.

Hare's Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991) is the measure of choice for measuring psychopathic personality disorder. An item response theory (00) approach was adopted to analyze both test and item functioning. Data from 2,067 North American participants were analyzed. The analysis confirmed that the test was appropriate for both the diagnosis of psychopathic personality disorder and for making measures of trait strength. 1\vo correlated but distinct factors underpin scores on the PCL-R: Factor I, Selfish, Callous, and Remorseless Use of Others, and Factor 2, Chronically Unstable and Antisocial Life style. Items related to Factor I are generally more discriminating and provide more information about the trait than items relating to Factor 2. Future uses of 00 procedures in the analysis of PCL-R data are discussed. Hare's Psychopathy Checklist (peL; Hare, 1980) and its recent revision (PCL-R; Hare, 1991) are rating scales designed to measure psychopathic personality disorder. The PCL-R uses information collected by interview and file review to rate the participant on 20 characteristics. These characteristics include the behavioral, affective, and interpersonal characteristics thought to define psychopathic personality disorder (Cleckley, 1976; Hare, 1970). The PCL-R is regarded as the instrument of choice for measuring psychopathic personality disorder (Conoley & Impara, 1995). The whole test can be used to provide either a diagnosis of psychopathy or a trait measure of psychopathic personality disorder (Hare et aI., 1990). The total test score provides an estimate of a higher order construct underpinned by two facets of psychopathic personality disorder (Hare et al., 1990). Detailed analysis has revealed that the factor structure underpinning the PCL and PCL-R can be best described in terms of two distinct yet correlated factors (Cooke, 1995a; Hare et aI., 1990; Harpur, Hare, & Hakstian, 1989). The first factor can be characterized as representing the "selfish, callous, and remorseless use of others" and is specified by core personality traits including superficiality, habitual lying, manipulativeness, and callousness, together with a lack of affect, guilt, remorse, and empathy. The second factor, which can be characterized as "chronically unstable and antisocial lifestyle," is specified by characteristics in