John F. Edens

Psychopathic, not psychopath: Taxometric evidence for the dimensional structure of psychopathy.

Although psychopathy is frequently regarded as qualitatively distinct from other conditions, relatively little research has examined whether psychopaths represent a distinct class of individuals. Using a sample of 876 prison inmates and court-ordered substance abuse patients who were administered the Psychopathy Checklist-Revised (R. D. Hare, 2003), the authors examined the latent structure of psychopathy using several taxometric procedures developed by Meehl and colleagues (P. E. Meehl & L. J. Yonce, 1994; N. G. Waller & P. E. Meehl, 1998). The results across these procedures offer no compelling support for the contention that psychopathy is a taxonic construct and contradict previous reports that psychopathy is underpinned by a latent taxon. The authors discuss the theoretical, public policy, and practice-level implications of these findings.

Psychopathic personality or personalities? Exploring potential variants of psychopathy and their implications for risk assessment

Although psychopathy typically has been construed as a relatively uniform construct, seminal theories and contemporary research suggest that it may be heterogeneous. In this article, the most promising literature is distilled to distinguish among potential variants of antisocial personality disorder (APD) that can be derived from, and informed by, modern conceptions of psychopathy. This analysis suggests that there are primary and secondary variants of psychopathy, which may be distinguished based on the extent to which they are heritable and are characterized by affective deficits, impulsivity, trait anxiety, and characteristics of borderline and narcissistic personality disorders (NPD). These variants also may differ in their patterns of violence and responsivity to treatment. If variants of psychopathy can be identified reliably and supported empirically, psychopathy may be transformed from a global label to a set of more specific constructs that improve our ability to understand, manage, and treat individuals who have largely been regarded as dangerous and untreatable.

Criterion-related validity of the Psychopathic Personality Inventory in a prison sample

The Psychopathic Personality Inventory (PPI; S. O. Lilienfeld & B. P. Andrews, 1996), a self-report measure of psychopathic personality features, and R. D. Hares (1991) Psychopathy Checklist-Revised (PCL-R) were administered to adult youthful offender prison inmates (N = 50). As hypothesized, PPI scores were significantly correlated with scores on the PCL-R, providing evidence of concurrent validity for the PPI. Moreover, unlike existing self-report psychopathy measures, the PPI showed a moderate and positive correlation with PCL-R Factor 1 (i.e., the core personality traits of psychopathy). Discriminant function analysis using the optimal PPI total score value to predict PCL-R classifications of psychopath (n = 10) and nonpsychopath (n = 40) resulted in accurate classification of 86% of the cases (sensitivity =.50, specificity =.95). Results are discussed in terms of the relative merits of these 2 measures of psychopathy and the validation of the PPI for clinical use.

A Taxometric Analysis of Psychopathic Personality.

Although a common assumption throughout much of the professional and popular literature is that psychopaths are qualitatively different from others, very few studies have examined the latent structure of psychopathy. Whether psychopathy is a discrete category or a continuous dimension may have implications for research on the assessment, etiology, and treatment of this disorder. This study examined the latent structure of psychopathy in a sample of 309 jail and prison inmates. Three taxometric procedures were used to analyze indicators drawn from the Psychopathic Personality Inventory (S. O. Lilienfeld & B. P. Andrews, 1996), a self-report instrument. Consistent with prior studies that used other measures of psychopathy, none of the analyses was consistent with a taxonic solution, suggesting that psychopathic personality may be best understood as existing on a continuum.

Does psychopathy predict institutional misconduct among adults? A meta-analytic investigation

Narrative reviews have raised several questions regarding the predictive validity of the Hare Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 2003) and related scales in institutional settings. In this meta-analysis, the authors coded 273 effect sizes to investigate the association between the Hare scales and a hierarchy of increasingly specific forms of institutional misconduct. Effect sizes for Total, Factor 1, and Factor 2 scores were quite heterogeneous overall and weakest for physically violent misconduct (r-sub(w) = .17, .14, and .15, respectively). Moderator analyses suggested that physical violence effect sizes were smaller in U.S. prison samples (r-sub(w) = .11) than in non-U.S. prison samples (r-sub(w) = .23). Findings are discussed in terms of the utility of the Hare measures for decision-making in institutional and other contexts.

Construct validity of the psychopathic personality inventory two-factor model with offenders.

Much of the research on psychopathy has treated it as a unitary construct operationalized by total scores on one (or more) measures. More recent studies on the Psychopathic Personality Inventory (PPI) suggest the existence of two distinct facets of psychopathy with unique external correlates. Here, the authors report reanalyses of two offender data sets that included scores on the PPI along with various theoretically relevant criterion variables. Consistent with hypotheses, the two PPI factors showed convergent and discriminant relations with criterion measures, many of which would otherwise have been obscured when relying on PPI total scores. These results highlight the importance of examining facets of psychopathy as well as total scores.

Prevalence of DSM-IV Substance Abuse and Dependence Disorders among Prison Inmates

The study examined the 30-day and lifetime prevalence of DSM-IV alcohol and drug disorders among state prison inmates. A sample of 400 inmates consecutively admitted to a state prison reception center were assessed for alcohol and drug disorders using the Structured Clinical Interview for DSM-IV (SCID-IV). Test-retest reliabilities were calculated for the SCID-IV. Lifetime substance abuse or dependence disorders were detected among 74% of inmates, including over half who were dependent on alcohol or drugs. For the 30 days prior to incarceration, over half of the sample were diagnosed as having substance abuse or dependence disorders, including 46% who were dependent on alcohol or drugs. Black inmates were significantly less likely to be diagnosed as alcohol dependent than whites or Hispanics. The high rates of substance use disorders are consistent with previous findings from other studies conducted in correctional settings and reflect the need to expand treatment capacity in prisons.

Using the PCL-R to Help Estimate the Validity of Two Self-Report Measures of Psychopathy With Offenders

Two self-report measures of psychopathy, Levenson’s Primary and Secondary Psychopathy scales (LPSP) and the Psychopathic Personality Inventory (PPI), were administered to a large sample of 1,603 offenders. The most widely researched measure of criminal psychopathy, the Hare Psychopathy Checklist—Revised (PCL-R), served as a provisional referent for estimating the construct validity of these self-report measures with offenders. Compared with the LPSP, the PPI displayed higher zero-order correlations with the PCL-R, better convergent and discriminant validity, and more consistent incremental utility in predicting PCL-R scores. Furthermore, using a variant of Westen and Rosenthal’s approach to evaluating the construct validity of a new measure, compared with the LPSP, the PPI’s pattern of associations with measures of 35 external criterion variables was more similar to the pattern observed for the PCL-R. Results generally provide stronger support for the validity of the PPI than the LPSP in offender populations using the PCL-R as a provisional benchmark, particularly for assessing interpersonal and affective features of psychopathy.

Use of the Personality Assessment Inventory to assess psychopathy in offender populations.

The authors investigated the validity of the Antisocial Features (ANT) scale of the Personality Assessment Inventory (PAI; L. C. Morey, 1991) with respect to assessments of psychopathy in 2 offender samples. Study 1 included 46 forensic psychiatric inpatients who were administered the Screening Version of the Hare Psychopathy Checklist (PCL:SV; S. D. Hart, D. N. Cox, & R. D. Hare, 1995). In Study 2, 55 sex offenders were administered the Hare Psychopathy Checklist--Revised (PCL-R; R. D. Hare, 1991). ANT scores correlated highly with the PCL:SV total score (r = .54) and moderately with the PCL-R total score (r = .40). ANT tapped primarily behavioral symptoms of psychopathy rather than interpersonal and affective symptoms. Also, ANT had low to moderate diagnostic efficiency regarding diagnoses of psychopathy, suggesting that it may be better used as a dimensional rather than categorical measure of this construct.

Identifying inmates at risk for disciplinary infractions: a comparison of two measures of psychopathy.

Poythress, Edens, and Lilienfeld (1998) recently reported a moderately strong correlation between Hares (1991) Psychopathy Checklist-Revised (PCL-R) and a newly developed self-report measure of psychopathy, the Psychopathic Personality Inventory (PPI) of Lilienfeld and Andrews (1996), in an ethnically diverse sample of 50 inmates from a youthful offender prison. The present study reports follow-up data regarding disciplinary infractions in this sample and examines the utility of the PCL-R and PPI for identifying those at risk for institutional misbehavior. Generally modest, but statistically significant, correlations were obtained between both measures and indices of aggressive institutional behavior. Multiple regression analyses revealed that both measures accounted for common variance in the criterion but that neither accounted for significant unique variance. Results are discussed in terms of the clinical utility of these measures in populations of young offenders.