Although most democratic theories assume that political participation other than voting constitutes an essential input to the political process, little is known about the cultural universality of this assumption. Drawing on cultural psychology findings derived from the widely shared framework of collectivism versus individualism, the present study tests the hypothesis that political demonstrators in collectivistic countries are socially avoided because they are perceived to be a threat to harmonious interpersonal relationships. A cross-national experiment in eight countries (US, UK, France, Germany, Japan, China, South Korea, and India) and one region (Hong Kong) indicated that political demonstrators are socially avoided, and this tendency was significantly stronger in collectivistic countries. Moderated-mediation analyses suggested that the social avoidance of political demonstrators in collectivistic countries is mediated by the perception that they are a threat to harmonious interpersonal relationships. The cross-cultural validity of democratic theory is discussed.