Reducing the Overlap Between Machiavellianism and Subclinical Psychopathy: The M7 and P7 Scales

Machiavellianism (Mach) and subclinical psychopathy are two widely studied antagonistic personality traits with distinct theoretical conceptualizations. Mach is conceptualized by strategic deviousness, cynicism, and pragmatic morality, whereas subclinical psychopathy is conceptualized by impulsive antisocial tendencies, callousness, and rule-breaking. However, existing measures of the two traits are typically highly correlated and have very similar nomological networks. Notably, even though psychopathy scales should be more strongly positively associated with antisocial impulsivity and more strongly negatively associated with conscientiousness than Mach scales, existing Mach and psychopathy scales tend to be similarly related to these constructs. We created a new Mach scale, the M7, and a new psychopathy scale, the P7, by selecting items from existing Mach and psychopathy scales on the basis of the correlations of these items with antisocial impulsivity and conscientiousness. Across three studies (combined N = 4,607), the M7 and P7 showed acceptable to good psychometric properties in terms of closeness to unidimensionality, measurement precision, temporal stability, measurement invariance across language and gender groups, and convergent and discriminant validity (nomological network, self-other agreement, and interpersonal perceptions in group interactions). Most importantly, the new scales assess clearly distinct latent traits that are more in line with their theoretical conceptualizations than established scales are