The Psychopathy Checklist
Dr. Robert D. Hare, PhD, one of the foremost experts on psychopathy, developed a 20-point checklist used in diagnosing psychopaths. It takes advanced education and substantial qualifications to use the list for diagnosing patients, and the list has been revised from its original form.
This list provides the full range of characteristics that a psychopath could have. You don't have to have all of these characteristics to be a psychopath, but you have to have been diagnosed with Conduct Disorder as a juvenile. According to some, the actual diagnostic term for psychopathy is Anti-Social Personality Disorder, but Dr. Hare says there's more to it. On Page 25 of his book Without Conscience, The Disturbing World of the Psychopaths Among Us, he says:
"The result has been confusion during the past decade, with many clinicians mistakenly assuming that Anti-Social Personality Disorder and Psychopathy are synonymous terms. As diagnosed by the DSM-III and the DSM-III-R, as well as by the recently published DSM-IV (1994), "Anti-Social Personality Disorder" refers primarily to a cluster of criminal and anti-social behaviors. The majority of criminals easily meet the criteria for such a diagnosis. "Psychopathy," on the other hand, is defined by a cluster of both personality traits and socially deviant behaviors. Most criminals are not psychopaths, and many of the individuals who manage to operate on the shady side of the law and remain out of prison are psychopaths."
Here is Dr. Hare's list of 20 characteristics potentially exhibited by psychopaths, as shown on Wikipedia. https://en.wikipedia.org/wiki/Psychopathy_Checklist
Each of the 20 items in the PCL-R is scored on a 3-point scale, with a rating of 0 if it does not apply at all, 1 if there is a partial match or mixed information, and 2 if there is a reasonably good match to the offender. This is to be done through a face-to-face interview together with supporting information on lifetime behavior (e.g., from case files). It can take up to three hours to collect and review the information.
Out of a maximum score of 40, the cut-off for the label of psychopath is 30 in the United States and 25 in the United Kingdom. A cut-off score of 25 is also sometimes used for research purposes.
