Arvan, M. Neuroethics (2013) 6: 307. doi:10.1007/s12152-011-9140-6
This study examined correlations between moral value judgments on a 17-item Moral Intuition Survey (MIS), and participant scores on the Short-D3 “Dark Triad” Personality Inventory—a measure of three related “dark and socially destructive” personality traits: Machiavellianism, Narcissism, and Psychopathy. Five hundred sixty-seven participants (302 male, 257 female, 2 transgendered; median age 28) were recruited online through Amazon Mechanical Turk and Yale Experiment Month web advertisements. Different responses to MIS items were initially hypothesized to be “conservative” or “liberal” in line with traditional public divides. Our demographic data confirmed all of these hypothesized categorizations. We then tested two broad, exploratory hypotheses: (H1) the hypothesis that there would be “many” significant correlations between conservative MIS judgments and the Dark Triad, and (H2) the hypothesis that there would be no significant correlations between liberal MIS judgments and Machiavellianism or Psychopathy, but “some” significant correlations between liberal MIS judgments and Narcissism. Because our hypotheses were exploratory and we ran a large number of statistical tests (62 total), we utilized a Bonferroni Correction to set a very high threshold for significance (p = .0008). Our results broadly supported our two hypotheses. We found eleven significant correlations between conservative MIS judgments and the Dark Triad—all at significance level of p < .00001—but no significant correlations between the Dark Triad and liberal MIS judgments. We believe that these results raise provocative moral questions about the personality bases of moral judgments. In particular, we propose that because the Short-D3 measures three “dark and antisocial” personality traits, our results raise some prima facie worries about the moral justification of some conservative moral judgments.