Comparing the Validity of Oblique Versus Orthogonal Factors of Subclinical Psychopathy

Recently, there has been some debate in the psychological literature involving the factor structure of subclinical psychopathy. Hare’s (2003) well-established theory involving an oblique (i.e., correlated) fourfactor solution has recently been challenged by an orthogonal (i.e., uncorrelated) two-factor solution. Using the Hare Self-Report Psychopathy Scale-III (SRP-III; four oblique factors) and the Psychopathic Personality Index (PPI; two orthogonal factors), we compared these two factor conceptions in an undergraduate sample (N = 274) on three main criteria: (1) intercorrelations among the psychopathy factors, (2) associations with self-reported delinquency, and (3) associations with Big Five personality factors. Results showed that the SRP-III factors and the PPI-Behavioral factor correlated strongly with each other, whereas the PPI-Personality factor did not correlate positively with the SRP-III factors or the PPI-Behavioral factor. Second, the PPI-Personality factor was not associated with delinquency, whereas each of the SRP-III factors and the PPI-Behavioral factor were correlated with delinquency. Finally, the SRP-III factors and the PPI-Behavioral factor showed expected correlations with the Big Five, whereas several PPI-Personality factor correlations contradicted the literature, including significant positive correlations with Agreeableness, Conscientiousness, and Emotional Stability. Together, these results suggest that the oblique SRP-III factor conception may be more legitimate than that of the orthogonal PPI factors, due to the questionable validity of the PPI-Personality factor. Furthermore, the oblique factor conception is more consistent with the notion that psychopathy is a coherent construct.