The origins of darkness: An evolutionary-developmental integration of Dark traits with the HEXACO

Exploitative, selfish behavior has been a topic of interest to researchers across a wide range of domains. One prominent area of research has focused on personality as an important contributor to harmful and selfish behavior. The term “Dark Triad” was coined to identify three selfish personality traits that all share a common core (D): Narcissism, Machiavellianism, and Psychopathy. While numerous candidates have emerged to explain D, evidence suggests that the HEXACO model of personality provides the best fit. In particular, the latent core of the HEXACO trait Honesty-Humility (H) appears to be statistically identical to the latent core of D (r ≈ 0.95). We adopt an evolutionary-developmental perspective to address how this common core may have emerged over evolution as well as developed in individuals. Specifically, we offer: 1) an adaptive explanation of high and low levels of H/D, 2) a parsimonious and plausible evolutionary and developmental model to explain the existence of Dark Triad traits that fits with both modern and historical patterns of human behavior, and 3) an explanation for how developmental and evolutionary processes of modification can change the levels of other HEXACO traits to lead to the expression of not only the Dark Triad, but to an entire array of Dark traits. We end by discussing implications for intervention and understanding personality models of exploitative, selfish traits.