A multi-study investigation assessing the potential redundancy among the Dark Tetrad using a narrowband trait approach.

We investigated the putative redundancy of the Dark Tetrad (specifically, Machiavellianism-psychopathy and sadism-psychopathy) through an examination of the differences between correlations with self-reported narrowband personality traits. In addition to measures of the Dark Tetrad, participants in four studies completed measures of various narrowband traits assessing general personality, aggression, impulsivity, Mimicry Deception Theory, and Reinforcement Sensitivity Theory. Results generally supported empirical distinctions between Machiavellianism and psychopathy, and between sadism and psychopathy. Machiavellianism significantly differed from psychopathy across correlations for nine of 10 traits (Study 1), 8 of 25 facets (Study 2), aggression (Study 3), 12 of 25 facets (Study 3), four of five facets (Study 4), impulsivity (Study 4), and five of six facets (Study 4). Sadism significantly differed from psychopathy across correlations with five of 10 traits (Study 1), eight of 25 facets (Study 2), reactive aggression (Study 3), 10 of 25 facets (Study 3), three of six facets (Study 4), impulsivity (Study 4), and three of six facets (Study 4). Our findings challenge the claims that Machiavellianism and psychopathy, as well as sadism and psychopathy, as currently measured, are redundant.