The disaggregation of the many components of psychopathy has received considerable research attention (Brinkley, Newman, Widiger, & Lynam, 2004; Cooke & Michie, 2001; Harpur, Hakistan, & Hare, 1988; Harpur, Hare, & Hakistan, 1989; Lynam & Widiger, 2007). Hare's (2003) Psychopathy Checklist Revised (PCL-R) importantly identified two separate factors, one representing the callous and remorseless use of others and the other representing a deviant and antisocial lifestyle. In the PCL-R, the two factors share only 25% of their variance (Harpur et al., 1988), and they have numerous different correlates (Harpur et al., 1989). Cooke and Michie (2001) identified three factors, described as (a) arrogant and deceitful interpersonal style, (b) deficient affective experience, and (c) impulsive and irresponsible behavioral style. To complicate matters further, the PCL-R does not include all of the dimensions of the classic description of psychopathy provided by Cleckley (1941); for example, low anxiousness is not represented (Lynam & Widiger, 2007; Rogers, 1995). Brinkley et al. (2004) elaborated by arguing that psychopathy, as measured by the PCL-R, is an etiologically heterogeneous entity. If psychopathy includes multiple dimensions that do not always covary, and if those dimensions have different etiologies, then psychopathy may not be a coherent, meaningful psychological construct.
