David Amodio, New York University and University of Amsterdam

How do explicit stereotypes become internalized as implicit prejudice? For example, when Donald Trump refers to Mexicans as criminals and rapists, one may dismiss it as political rhetoric. Yet this information is nonetheless encoded in the mind, from where it may influence subsequent interactions with group members in a way that induces implicit bias. I will describe research from my lab on how exposure to explicit semantic messages (e.g., stereotypes) can influence direct interactive social learning, via reward reinforcement, to produce implicit bias. We show that, once formed, this bias is expressed in choice behavior and trust decisions, without participants’ apparent awareness and against their economic interests, and transmitted to unwitting observers who have no knowledge of group stereotypes. Computational modeling suggests this effect involves biased expectancies (priors) combined with biased updating (learning rate) during interactions with group members. These findings support a novel account of implicit bias formation, based on models of interactive learning systems, with implications for how bias is propagated and potentially reduced.