HERO or DT, what comes first? The causal relationship between psychological capital and dark tetrad differed

Research on the association of the Dark Tetrad (DT) personalities and psychological capital (PsyCap) has been insufficient. Most of the existing studies regarded PsyCap as a consequence of personality differences and took it as an internal mechanism between personality and outcome variables. However, the exact causality of personality and PsyCap is still unclear. Thus, we aimed at proving the causal relationship (Study 1) and mediating role of PsyCap between DT and health variables (Study 2). In study 1, a total of 373 students (aged 17 to 25) participated in the 10-months longitudinal study and filled questionnaires concerning the DT and PsyCap. In study 2, a total of 858 young adults (aged 18 to 25) completed questionnaires of the DT, PsyCap, and health. All components of the dark personality and PsyCap remain stable across time. The negative correlation between psychopathy and PsyCap was the closest, followed by Machiavellianism and sadism. Narcissism was positively related to PsyCap. Primary psychopathy, secondary psychopathy, narcissism, and Machiavellianism were antecedents of PsyCap, while PsyCap merely was the predictor of sadism. PsyCap mediated the association of dark personalities and health. Our findings uncovered the association of the DT and PsyCap and further confirmed the uniqueness of the four components of the DT, which might be explained by PsyCap. Moreover, PsyCap does link the tie between dark personalities and health.