Sadistic Offender or Sexual Sadism? Taxometric Evidence for a Dimensional Structure of Sexual Sadism

Nicholas Longpré, Jean-Pierre Guay, Raymond A. Knight, Massil Benbouriche

Severe sexual sadism is a disorder of sexual preferences that focuses on humiliation and domination of the victim, sometimes causing grievous injury or death. Because offenders with high levels of sadism represent a risk to both reoffend and cause considerable harm should they reoffend, a diagnosis of sexual sadism has serious implications. The actual diagnosis of sexual sadism is fraught with problems (i.e., low reliability and validity) and exhibits poor consistency across assessments and studies (Levenson, 2004; Marshall, Kennedy, & Yates, 2002a). Various authors have proposed that sadism should be reconceptualized and have suggested that a dimensional approach may be more effective than a classificatory one for diagnosing sexual sadism (e.g., Marshall & Kennedy, 2003; Nietschke, Osterheider, & Mokros, 2009b). The dimension versus taxon question also impacts debates about the etiology and treatment of sadism. We assessed the taxonicity of sexual sadism by conducting a taxometric analysis of the scores of 474 sex offenders from penitentiary settings on the MTC Sexual Sadism Scale, using Meehl's taxometric methods (Meehl & Yonce, 1994; Waller & Meehl, 1998). Findings indicated that sexual sadism presents a clear underlying dimensional structure. These results are consistent with earlier research supporting a dimensional assessment of sexual sadism and indicate that the diagnosis of sexual sadism should be reconceptualized. The theoretical and clinical implications of these findings are discussed.