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It's Harder to Spot a Psychopath Than You Might Think

New research puts the most well-established psychopath test to the test.

Alex Brylov/Shutterstock
Source: Alex Brylov/Shutterstock

When it comes to measuring psychopathy, perhaps the favorite instrument used by forensic psychologists and psychiatrists is the Hare Psychopathy Checklist-Revised (PCL-R), developed by Canadian psychologist Robert D. Hare in 1991 and revamped in 2003. Teaming up with Carleton University’s Julie Blais and Adelle Forth, Hare (now at University of British Columbia), examined over 20 years of data on the measure’s reliability using data from workshops in which trainees learned how to administer the PCL-R (Blais et al., 2017). Because the PCL-R is administered as a clinical interview, professionals who wish to gain proficiency in its use must be trained so that they are able to provide accurate assessments. The training workshops involve 2 to 3 days of intensive education in which they practice by rating excerpts from actual cases using portions of videotaped interviews, transcripts of full interviews, and file reviews. Their coding of the case studies are then used to determine if trainees are ready to use the PCL-R in their practice, for research purposes or as part of a forensic evaluation.

Questionnaire measures of psychopathy exist, including self-report versions. The PCL-R is more time intensive to administer and score, but the rationale is that it provides a more accurate basis for making decisions that will determine the potential psychopath's fate. For example, as noted by Blais and colleagues, the PCL-R and its related measures are used in criminal justice settings to estimate the risk of an individual’s dangerousness, readiness for parole, and even whether he or she should receive the death penalty. One of the questions that therefore arises when considering evidence provided by the PCL-R is whether the people conducting the assessment are providing accurate and consistent, or reliable, ratings.

It’s important to understand, then, that the PCL-R isn’t just used to describe people who, for example, appear to be heartless or exploitative in their relationships. The term “psychopathy” is used colloquially outside of the formal evaluation settings in which the PCL-R provides a clinical assessment. Additionally, people can be high on the personality trait of psychopathy as determined by one of those self-report questionnaires, but still not fit the clinical definition of antisocial personality disorder or ultimately be deemed a violent offender who is unlikely to reform.

Nevertheless, the PCL-R has provided fascinating analyses of psychopathy in “everyday life,” as shown in Jon Ronson’s The Psychopath Test. Ronson participated in training sessions for the PCL-R, partnering with Hare in providing his insightful analysis of how the test could be applied not only to prisoners, but also to people who engage in serious psychopathic behaviors outside of clinical settings. It’s important to keep in mind that Ronson didn’t take the term “psychopath” lightly, nor did he thoughtlessly apply the label to the subjects of those he profiled.

Returning to the Carleton University study, Blais and her colleagues analyzed the agreement in ratings performed by 280 trainees who participated in PCL-R workshops, half of whom had a doctorate in psychology and nearly 40 percent of whom had a master’s degree. The participants rated 6 cases who ranged in validated PCL-R scores from low to high, all of whom were male, 5 of whom were convicted of assault or homicide. The remaining case had committed a variety of offenses, including impaired driving and theft, as well as possession of narcotics. Each item in the PCL-R’s agreement was calculated among the trainees, as was agreement in total scores.

The PCL-R itself is a 20-item “construct” rating scale, meaning that items are scored based on the assessor’s evaluation of all data relevant to that item. The four facets of the PCL-R include Interpersonal, Affective, Lifestyle, and Antisocial, which combine into two higher-order factors of Interpersonal/Affective (e.g., glibness, lack of remorse, grandiosity) and Lifestyle/Antisocial (high-risk, impulsive, and criminal behavior).

The Canadian team’s analysis of the agreement statistics led them to conclude that the individual items on the PCL-R were not actually all that reliable. Similarly, total PCL-R scores and scores for the two factors were not all that reliable either. However, the agreement among raters varied according to whether the cases were high, moderate, or low in psychopathy. There was much higher agreement when the case study himself had high psychopathy scores. In other words, almost anyone trained in the PCL-R can spot a psychopath if the individual is psychopathic enough. Furthermore, there was one item that did receive suitably high inter-rater agreement, and that was “Need for stimulation.” The least reliable included “Failure to accept responsibility” and (not surprisingly) “Pathological lying."

As the authors point out, these findings don’t mean that the PCL-R is a worthless clinical tool. The cases were not rated as they would be in real life, where the interview would be administered in person. In the field, trained administrators of the PCL-R would be able to ask follow-up questions and judge nonverbal behavior in ways not possible even from video recordings.

There remains, additionally, the possibility that some people are better than others in using the PCL-R. Blais and her colleagues noted that personal biases, objectivity, interpersonal skills, and tough versus tender-mindedness can all come into play when you’re confronted with evaluating someone’s psychopathic tendencies. Just receiving the training, even if it does go on for 2 or 3 days, isn’t enough to produce a qualified psychopathy rater.

What do these findings imply for nonprofessionals who must, in their day-to-day lives, decide whether they’re dealing with a psychopath? How about if you’re trying to decide whether to hire a baby-sitter, trust a salesperson, or go out with someone you’ve just met? The study’s upshot is that at moderate to low levels of psychopathy, it can indeed be difficult to provide an accurate assessment, even if you’ve received official training. When the individual’s behavior, interpersonal style, and history are more overtly psychopathic, less sensitivity is required by anyone providing an assessment. You'll also find it harder, for obvious reasons, to detect lying than you would behavior that suggests the person is always seeking new and riskier experiences.

The other takeaway message is that some people are better than others at figuring out whether they can trust the person they’re interacting with to be an honest, sensitive, and reliable individual. If you’re attracted to someone, even if you’re a great judge of character, your perceptiveness may be dulled. Be wary of the warning signs, and you’ll be better able to trust that your faith in the other person is indeed warranted.

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Copyright Susan Krauss Whitbourne 2017


Blais, J., Forth, A. E., & Hare, R. D. (2017). Examining the interrater reliability of the Hare Psychopathy Checklist—Revised across a large sample of trained raters. Psychological Assessment, 29(6), 762-775. doi:10.1037/pas0000455