You're red, I'm blue, so I don't like you: the political dissimilarity-disliking effect

Decades of research suggest that people like politically similar others more than dissimilar others, yet few studies use a control group in their design, making it unclear whether similarity drives liking or, consistent with negative partisanship and affective polarization, dissimilarity drives disliking. Two studies tested a political similarity-liking effect in the current polarized political climate by examining whether sharing real news articles suggesting endorsement of political parties or politicians (Study 1; N = 452) or sharing events supporting partisan issues or parties (Study 2; N = 713) on Facebook would influence people's initial impressions of a Facebook profile-owner. Participants did not report liking political ingroup members more than a neutral control. Instead, participants disliked political outgroup members more; this pattern was mediated by both positive and negative emotional responses to the profiles shared. These results suggest not a partisan similarity-liking effect, but rather a dissimilarity-disliking effect consistent with negative partisanship that may stem from the emotional reactions associated with the current political landscape.