Political Participation Under Uncertain Norms

Democracies can sustain disagreement over outcomes, but they are harder to sustain when citizens also perceive the governing norms of political contestation as settled along partisan lines. We study this problem in the context of Brexit and experimentally vary truthful information about how much Leave and Remain supporters agree with, and how uncertain they are about, the appropriateness of a second referendum. We find that uncertainty matters more than agreement: respondents become more willing to donate to and tweet for campaigns on either side of the referendum question when they learn that others, especially members of their own political camp, are more uncertain about the norm. The pattern is strongest for support for the norm position that is less popular within one's own political camp, while private beliefs about the norm and about Brexit itself barely move. These findings are more consistent with reduced conformity pressure and higher perceived returns to political expression than with private-belief updating, and they suggest that information about uncertainty can generate a meaningful form of depolarization in democratic engagement even when underlying outcome preferences remain largely unchanged.