Understanding the structure of the psychopathy checklist - revised: an exploration of methodological confusion.

Psychopathy is the key construct in the Dangerous and Severe Personality Disorder (DSPD) Programme. The Psychopathy Checklist - Revised is used as a primary means of selection for the programme. The Checklist confounds two distinct constructs - personality disorder and criminal behaviour. This confound is important both practically and theoretically. For example, under the criteria for DSPD it is necessary to demonstrate that personality disorder has a functional link with future risk of criminal behaviour. The confound has been exacerbated recently by claims that criminal behaviour is a core feature of psychopathic disorder. This contention is based on inappropriate analytical methods. In this paper we examine the source of this confound and illustrate how inappropriate methods can mislead.