Is the Short Dark Tetrad really a tetrad? It depends on how you define everyday sadism

The present study evaluates the factor structure of the Short Dark Tetrad (SD4), a measureassessing Machiavellianism, grandiose narcissism, psychopathy, and everyday sadism. Using alarge-scale, cross-sectional dataset, we compared nine models to determine the optimal factorrepresentation of the SD4. We found a bifactor model provided the best fit, with separate specificfactors for Machiavellianism/psychopathy, grandiose narcissism, and everyday sadism in additionto a global latent factor. This finding suggests that the four subscales are united by a commoncore. Moreover, it indicates the unique aspects of Machiavellianism and psychopathy representopposite ends of the same dimension and the sadism subscale is empirically distinct from thepsychopathy subscale. However, the differentiation between the sadism and psychopathysubscales appears to primarily be a consequence of the sadism subscale being defined almostentirely by vicarious sadism. Taken together, these findings contribute to our understanding ofantagonistic personality traits, while also pointing to the need for further refinement in themeasurement of everyday sadism within the SD4.