Recently there has been the suggestion that the Dark Triad traits (Machiavellianism, narcissism, and subclinical psychopathy) share a common overlapping core. In this exploratory investigation, a secondary data analyses was conducted to extract a common Dark Triad core, the Dark factor. We found that Machiavellianism and psychopathy had higher factor loadings on the Dark factor than narcissism. The Dark factor was best explained by genetic and unique environmental factors when sex and age effects were removed. Genetic and unique environment models best fit the residuals for Machiavellianism and psychopathy (and narcissism, but only when sex and age were removed). These results suggest that further behavior genetic studies should be conducted on the common and unique variances of the Dark Triad.