When bias binds: Effect of implicit outgroup bias on ingroup affiliation.

We tested a novel process we term implicit homophily in which perceivers' implicit outgroup bias shapes their affiliative responses toward ingroup targets with outgroup friends as a function of perceived similarity. Across 4 studies, we tested implicit homophily in the context of racial groups. We found that White participants with higher implicit anti-Black bias reported less affiliative responses toward White targets with Black friends compared with White targets with White friends, and this effect persisted above and beyond the effects of implicit pro-White bias and explicit racial bias (Studies 1-3). We further found evidence that this relationship between implicit anti-Black bias and affiliation exists because participants infer how comfortable targets are around outgroup members (Preliminary Study) and use this information to infer similarity on this dimension (Studies 1-3). Our findings also suggested that stigma transference and expectancy violation were not viable alternative mediators (Preliminary Study and Study 1). Finally, women's implicit anti-Black bias predicted their likelihood of having Facebook friends with Black friends, providing ecological and behavioral evidence of implicit homophily (Study 4). Implications for research on stigma by association, extended contact, affiliation, and network formation are discussed.