From the Drs. Skeem and Cooke article that got Dr. Robert Hare's panties all in a wad about the validity of his PCL-R (Psychopathy Checklist Revisited):
“Without a history of violent or criminal behavior, even an individual with pronounced interpersonal and affective traits of psychopathy is unlikely to surpass the PCL–R’s threshold score for diagnosing psychopathy.”(Email me if you would like to read the article in its entirety.)
“We specifically argue that the process of understanding and appropriately diagnosing psychopathy must be separated from the enterprise of predicting violence.”
“First, the PCL–R is a measure that imperfectly maps psychopathy, the domain of interest. Second, the PCL–R’s factor structure is not a conceptualization of, or explanation for, psychopathy and does not fully correspond to Cleckley’s (1941) conceptualization, on which it is purportedly based. Third, reification of the PCL–R forecloses on the possibility of iteratively using theory and empirical results to revise this tool (and others) to advance understanding of psychopathy.”
“’Thanks to Hare, we now understand that the great majority of psychopaths are not violent criminals and never will be. Hundreds of thousands of psychopaths live and work and prey among us’ (Hercz, 2001, ¶ 11). The two-factor model poorly identifies this “great majority of psychopaths” who escape contact with the legal system or simply express their psychopathic tendencies in a manner that does not conflict with the law.”
“Beyond past criminal behavior, adding such variables as gender, age, or substance abuse to the PCL–R might also improve prediction of violence. Such an improvement would not imply that these characteristics are central to psychopathy.”
“The pursuit of validly diagnosing a personality disorder is distinct from the enterprise of predicting violence.”