Reproductive ecology of dark personalities: Dark Tetrad traits, criminal career, and fertility

Research on the links between “dark” personality traits and fertility is scarce, despite its conceptual significance – examining the links between behavioral traits and fertility is a pivotal step in analyzing the current evolution of the traits. We examined the associations between the Dark Tetrad traits (psychopathy, narcissism, Machiavellianism, and sadism) and fertility (measured by the number of children) in a sample of Serbian prisoners (N = 590). Additionally, we examined how the duration, magnitude, and versatility of criminal behavior (i.e., criminal career) is associated with fertility, including its mediating role in the link between the Dark Tetrad and fertility. Correlation analysis showed negative associations between sadism, psychopathy, Machiavellianism, criminal career, and fertility. The two latter associations were confirmed in the regression analysis and extended by the positive contribution of narcissism to the prediction. Finally, path analysis showed that a criminal career fully mediates the negative association between psychopathy and fertility and partially mediates the association between Machiavellianism and fertility; narcissim had positive path to fertility in this analysis as well. Hence, the research results showed that criminal behavior, as one of the behavioral outcomes of the Dark Tetrad traits, may be involved in a decrease in reproductive fitness and thus produce fitness costs for the dark traits themselves, particularly psychopathy and Machiavellianism.