Hare, Robert D.: Psychopathy and Crime

The Psychopathy Checklists

Hare is most well-known for his efforts at operationalizing the construct of psychopathy. Specifically, he developed the Psychopathy Checklist—Revised (PCL-R). The PCL-R is a 20-item measure that assesses four facets of psychopathy. One facet is labeled interpersonal, and includes traits that assess the manipulative, conning, and deceitful interpersonal styles exhibited by psychopathic individuals. The second facet is referred to as the affective component and taps into the callous, unfeeling, and remorseless emotional life experienced by psychopathic individuals. These two facets form what has traditionally been referred to as factor 1 of psychopathy. The second factor also contains two, lower-order facets. The behavioral facet refers to the impulsive and irresponsible manner in which psychopathic individuals typically behave. The fourth facet, labeled antisocial, measures the early and persistent aggression, delinquent, and criminal behavior characteristic of psychopathic personality disorder.

The purpose of the PCL-R is to measure the extent to which an individual possesses the traits and behaviors characteristic of psychopathy. For each of the 20 items, individuals can be scored as 0 (does not apply), 1 (applies to some extent), or 2 (definitely applies), resulting in a possible range of 0–40. The score is based on two sources: a review of file data (e.g., an individual's prison records) and an in-depth interview. Although scores from the PCL-R are normally distributed (Hare, 2003), there are guidelines that have been developed to designate a clinical cutoff. Specifically, an individual who receives a score of 30 or more is deemed to be psychopathic. From a clinical standpoint, there needs to be a score at which a diagnosis can be made. Moreover, some research suggests that psychopathy is categorical, meaning that those scoring above a certain threshold (in this case, 30 or greater) are qualitatively distinct from those scoring under the threshold. However, other studies have failed to replicate this finding, which is consistent with how others view psychopathy as existing on a continuum.

The taxometric analyses aside, the PCL-R has demonstrated sound psychometric properties in several other domains. For example, Hare and Craig Neumann provide compelling evidence regarding the internal consistency of the 20 items (a ranges from .81 to .89). Despite the fact that clinical judgment is required to score the PCL-R, Hare and Neumann found that interrater reliabilities are quite high (ICCs range from .88 to .97). In addition, Hare's 2003 research indicates that the factor structure of the PCL-R is stable. However, there is an ongoing debate of whether psychopathy is better represented by three or four factors. Because the PCL-R has shown such strong psychometric properties and has substantial clinical utility, it is considered to be the gold standard for measuring psychopathy.

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