Selective Similarity Preference: People with a “Darker Core” Desire More Partner Similarity in Dark Traits but Not in Big Five

Research on assortative mating has shown that couples share strong similarities in demographic and attitudinal variables, while the similarity in personality is generally weak. However, a recent meta-analysis indicated that couple similarity in dark traits is considerably greater than that in the Big Five. If these differential similarities are primarily due to active preference, we expect that (1) the desire for similarity in dark traits should be higher than that for the Big Five and (2) the strongest desire for partner similarity in dark traits should come from the “darkest” individuals (i.e., with the darkest core). Participants (n = 2465) rated themselves and their ideal partner in Dark Triad and Big Five traits. They also rated their own dark core. The results showed consistent evidence for desired similarity in dark traits; however, this similarity was no greater than that for the Big Five. Further, dark core generally moderated desired similarity on dark traits such that people with a darker core preferred stronger partner similarity in dark traits. This pattern was only observed for Agreeableness on the Big Five. A new explanation was proposed to reconcile these paradoxical findings concerning desired and actual similarity in dark traits in comparison to the Big Five.