Exploring the History and Features of the Psychopathy Checklist-Revised: 2nd Edition

Exploring the History and Features of the Psychopathy Checklist-Revised: 2nd Edition

The evaluation of psychopathy has a rich and extensive history. Beginning with the initial reflections of trailblazing psychologists and psychiatrists, extending to Cleckley’s (1976) formulation of 16 diagnostic criteria for identifying psychopathy. No more is this history prevalent than in the work of Robert D. Hare, the author of MHS’ Hare Psychopathy Checklist–Revised: 2nd Edition (PCL–R: 2).

The PCL–R: 2 is a 20-item scale used to assess psychopathy in various settings, including clinical, forensic, and research contexts, for individuals 18 years and above (Hare, 2003). The PCL–R: 2 uses a semi-structured interview, a file review, and collateral information to measure inferred personality traits and behaviors related to a widely understood, traditional conception of psychopathy. The measure is supported by a variety of other assessments Dr. Hare developed, including a screening version, the Hare Psychopathy Checklist: Screening Version (PCL:SV), and a youth version, the Hare Psychopathy Checklist: Youth Version (PCL:YV). The Hare Psychopathy Checklist–Revised (PCL–R; the predecessor to PCL–R: 2) use is most widespread within the criminal justice system, where it has been referred to as the “gold standard” for identifying psychopathy (Edens et al., 2001). Below, we explore the historical background of the PCL–R: 2, the rationale behind its development, and its features.

The need for a measure of psychopathy

The Hare Psychopathy Checklist (PCL; the early predecessor of the PCL–R: 2) was initially developed in the 1970s by Canadian psychologist Robert D. Hare. At the time, Dr. Hare and his colleagues noticed that available assessment procedures for psychopathy, including those based on clinical diagnosis and self-report inventories, lacked demonstrated reliability and validity. In essence, a person could reasonably be diagnosed with psychopathy because of one psychiatrist’s opinion, without the requirement for any formal assessment process or understanding of the presentation of psychopathic characteristics. It was entirely feasible, based on a lack of a unified definition or formal approach for diagnosis, that someone presenting with a personality disorder could instead be diagnosed as a “psychopath.”  Dr. Hare’s research on psychopathy, coupled with the development of the PCL, contributed to the establishment of an operationalized definition for psychopathy (Hare, 2003). This early version of the PCL offered researchers and users a standard metric for determining psychopathy (Hare, 2003).

The PCL underwent updates over time to incorporate more comprehensive administration and scoring instructions, ultimately resulting in the release of the PCL-R in 1991. While the research literature attesting to the PCL and PCL–R psychometric properties grew over the years, one of the development goals of the PCL–R: 2 was to further address applicability of the measure with regards to diverse groups. The PCL–R: 2 now has additional validation data for some critical diverse populations and justice-involved individuals from outside North America. The PCL–R: 2 gained international prominence as it garnered support from scholars worldwide through continuous research efforts.

What’s different in the PCL-R: 2 compared to the PCL-R?


  • A large amount of validation data enables descriptive statistics and comparison tables for specific justice-involved individuals for more robust interpretation of scores across a wider group of individuals.
  • More data addresses vital issues such as reliability, validity, and generalizability. The PCL–R: 2 manual includes additional information on female justice-involved individuals, different ethnic identities, and justice-involved individuals with substance use disorders.
  • New validation data resolves issues for users who produce psychological reports for the criminal justice system or who testify in court based on outdated information in the older PCL–R manual.
  • Additional international validation samples enable scoring across diverse groups from across the world.


  • Because the PCL–R: 2 did not adjust scoring guidelines, those who are trained to use the PCL–R may also use the new version.


  • The PCL–R: 2 uses gender-inclusive language across both its items and interview guides.


  • The PCL–R: 2 includes instructions throughout the manual for those opting to reference research in a court setting.

The Official Hare PCL–R: 2 Training Program

Training for the PCL–R: 2 is offered by MHS in an easy to access online format. Comprised of an on-demand presentation and a live Q&A by the instrument’s author, Dr. Hare and a two-day live, interactive webinar by a thought leader in the field of psychopathy, Dr. J. Reid Meloy. This innovative program trains attendees in how to use the PCL–R: 2 while earning 16 hours of valuable Continuing Education Credit. The training covers the following:

  • Item-by-item instructions are given on how to reliably score the measures and interpret their findings.
  • A review of the peer-reviewed research on the PCL–R: 2 is provided.
  • Guidance will be put forth on how to apply reporting conventions.
  • Case studies will be employed to allow you to practice using the instruments and to learn to avoid common administration errors.

Learn more about when the next Official Hare PCL–R: 2 Training Program is available.

The PCL–R: 2 is a useful diagnostic tool in forensic populations and research. It is imperative that this tool is only used by professionals who have been specifically trained in its use and who have a comprehensive understanding of the current literature pertaining to psychopathy (Oliver & Wong, 2015). Notwithstanding, when used by competent professionals, the PCL–R: 2 is a reliable and valid tool for diagnosing psychopathy in forensic settings.


Cleckley, M. H (1976). The mask of sanity: an attempt to clarify some issues about the so-called psychopathic personality (5th ed.). Mosby.

Edens, F. J., Skeem, L. J., Cruise, R. K., & Cauffman, E. (2001). Assessment of “juvenile psychopathy” and its association with violence: a critical review. Behavioral Sciences & the Law, 19(1), 53–80. https://doi.org/10.1002/bsl.425

Olver, E. M, & Wong, C. P. S. (2015). Short- and Long-Term Recidivism Prediction of the PCL–R and the Effects of Age: A 24-Year Follow-Up. Personality Disorders, 6(1), 97–105. https://doi.org/10.1037/per0000095

Hare, D. R. (2003). Hare Psychopathy Checklist-Revised (PCL–R) 2nd Edition Technical Manual. Multi-Health Systems Inc.

Hare, D. R., & Neumann, C. (2008). Psychopathy as a Clinical and Empirical Construct. Annual Review of Clinical Psychology. 4. 217-24. 10.1146/annurev.clinpsy.3.022806.091452.

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