Ingroup Bias in Social Information Search and Use

Social information helps improve judgments. While studies often examine how individuals use social information, few focus on the active process of searching for it, or linking the two. We examined how partisanship, an identity known to cause strong ingroup biases and polarisation, affects both social information search and use across four decision-making studies. Partisan biases emerged at distinct stages of information processing. When partisan identity was salient (election prediction), participants preferentially initiated information search from their ingroup. However, once information-seeking began, participants explored ingroup and outgroup decisions equally. Despite balanced exploration, biases re-emerged during information use: Participants relied more heavily on ingroup members’ choices and on information that aligned with their preferred political outcomes. These findings demonstrate the importance of disentangling social information search and use. They suggest that polarisation may stem less from a refusal to explore opposing views, and more from how that information is used.