Democracy relies on citizens who are politically knowledgeable and engaged. However, when a voter gains political knowledge regarding important issues, through television, town halls, or social media, she also learns that there are many other politically knowledgeable voters, highlighting the importance of social knowledge in political participation. Will a voter with concrete—as opposed to hypothetical—knowledge about other voters’ political knowledge have an increased incentive to participate? Or instead, will concrete social knowledge about other voters actually inhibit participation? In this article, we develop a novel experimental design that focuses on whether concrete knowledge about other voters’ political knowledge influences political participation. Our main result shows that concrete social knowledge decreases individual voters’ willingness to vote, and thereby reduces the probability democracy chooses the majority preferred alternative, i.e. the quality of democratic choice.