INTERPERSONAL RELATIONS AND GROUP PROCESSES When Bias Binds: Effect of Implicit Outgroup Bias on Ingroup Affiliation Drew S. Jacoby-Senghor Columbia University Stacey Sinclair Princeton University Colin Tucker Smith University of Florida 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. Keywords: implicit bias, similarity, affiliation, stigma by association, extended contact Supplemental materials: http://dx.doi.org/10.1037/a0039513.supp It is well documented that implicit outgroup bias impairs individ- uals’ intergroup interactions (Dasgupta, 2004; Greenwald, Poehlman, Uhlmann, & Banaji, 2009; Jost et al., 2009). However, the impact of outgroup bias on ingroup affiliation may be currently underappreci- ated. In the present research we propose that irrespective of explicitly espoused group-based attitudes, people may be subtly attracted to ingroup members they perceive as having the same subjective re- sponses to intergroup contact, a process we have termed implicit homophily. Specifically, we hypothesize that because implicit bias predicts one’s responses toward outgroup members, it may also pre- dict one’s perceived similarity to ingroup members in response to their degree of intergroup interaction. For example, an individual with high implicit anti-Black bias may be less likely than an individual with low implicit bias to perceive a person with Black friends as being similar to herself—regardless of her implicit ingroup favoritism or whether she believes herself to have positive or negative attitudes toward Blacks. In turn, one’s level of perceived similarity to another person should predict affiliative responses toward them (Berscheid, 1985). We test this implicit homophily hypothesis in an interracial context and show that implicit racial bias predicts liking of ingroup members via perceived similarity. Implicit homophily has numerous implications. Theoretically, the proposed process informs extant research on stigma by association (Goffman, 1963) and provides a new perspective on the mechanisms affecting how nonstigmatized individuals are evaluated in light of associations with stigmatized others. Rather than being driven by transference of stigma from one person to another, implicit homophily suggests that individuals with a similar response to a third party may experience similarity-based attraction. Therefore, observed intergroup contact can have either a positive or negative impact on ingroup affiliation depending on the perceiver’s implicit bias. Implicit homophily also has practical implications insofar as this process determines the likelihood that one might meet outgroup Editor’s Note. Ashby Plant served as the guest editor for this arti- cle.—KK Drew S. Jacoby-Senghor, Columbia Business School, Columbia Univer- sity; Stacey Sinclair, Department of Psychology, Princeton University; Colin Tucker Smith, Department of Psychology, University of Florida. We extend thanks to colleagues who provided critical feedback on earlier versions of this research, in particular Nicole Shelton, Nick Turk- Browne, Andrew Conway, and Andreana Kendrick. Thanks also to lab- mates who provided comments on this work and to the numerous research assistants (Eri Adriola, Maddy Bernstein, Carina Chang, Stephanie Collelo, Rich Daker, Malena de la Fuente, Margaret Hua, Phoebe Huang, Julie Kwong, Young Sun Kim, Megan Nelson, Eunhae Oh, Deborah Sandoval, Annie Tornabene, and Emmy Williams) who aided in collection of these data and preparation of the article. Correspondence concerning this article should be addressed to Drew S. Jacoby-Senghor, Uris Hall, 3022 Broadway, New York, NY 10027-6902. E-mail: dsenghor@gmail.com This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Journal of Personality and Social Psychology, 2015, Vol. 109, No. 3, 415– 433 © 2015 American Psychological Association 0022-3514/15/$12.00 http://dx.doi.org/10.1037/a0039513 415