an examination of the factor structure of the psychopathy checklist

Given the relationships between the interpersonal and affective traits of
psychopathy and instrumental aggression demonstrated in the studies described above,
it is not surprising that these traits have been used as a potential explanation for
aggressive and antisocial behaviour in youth (e.g., Frick & White, 2008). In fact, Frick
and White argue that some of the most severely violent and aggressive youth are
distinguished by callous-unemotional (CU) traits. CU traits, as defined by Frick include;
lack of guilt, lack of empathy, and callous use of others for one’s own gain and are
represented by Factor 1 of Hare’s two-factor model, Factor 2 of Cooke and Michie’s
three-factor model, and Facet 2 of Hare’s four-facet model of the PCL:YV. Indeed, high
CU traits, particularly when combined with conduct problems, are not only related to
increases in overall levels of aggression, but specifically to increases in instrumental
aggression (Frick et al., 2003; Frick & White, 2008; Waschbusch & Willoughby, 2008).
Frick and colleagues (Frick et al., 2000) have even suggested that it is the presence of
these specific CU traits that differentiates individuals with high levels of psychopathic
traits. Frick and White (2008) reviewed the extant literature on CU traits in youth and
found that CU traits were stable across development, and that the presence of CU traits
reliably distinguished a small group of aggressive and antisocial youth. Further,
longitudinal studies have shown that the presence of CU traits in childhood and early
adolescence predicts psychopathy in adulthood with clinic-referred youth, after
controlling for other risk factors, such as parental psychopathology, parenting
behaviours, and demographic factors (Burke, Loeber, & Lahey, 2007). The literature
also suggests that heritability of antisocial behaviour is greater when present along with
CU traits (Viding, Jones, Frick, Moffitt, & Plomin, 2008). Considering these findings, the
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