Social scientists often characterize identity politics as a threat to democracy and growth, and recent scholarship investigates factors that could exacerbate or alleviate it. A dominant view — that shared social identity acts as a heuristic in low-information contexts — implies that information access could reduce social identity voting. But this view contrasts with evidence that identity often conditions information processing, potentially in ways that amplify in-group preferences. We test these expectations with a field experiment around Benin's 2015 legislative elections. Behavioral and attitudinal data reveal that voters reward good-performing incumbents only if they are coethnics, and punish bad performers only if they are noncoethnics. Coethnics are also more (less) likely to accurately recall performance information if it is positive (negative). These results are consistent with a theory of motivated reasoning whereby voters act on new information only when it allows them to reaffirm their social identity. These findings improve our understanding of comparative ethnic politics, identity and information processing, and information and accountability.