Scholars of democratization have developed a variety of theories to explain national and cross-national differences in democratic support. These theories, however, pay little attention to the cognitive origin of democratic support. This study seeks to examine how informed understanding about democracy affects such support. To this end, it applies theories of institutional legitimacy and social learning and predicts that the relationship between citizen understanding of and support for democracy is not only positively concaved but also dependent on the historical experience of democracy. An analysis of the World Values Survey 2005–2008 reveals strong evidence to support the theoretical predications.