One of the most important developments in international political and legal theory over the last 15 years has been the assertion that norms affect state behavior. Scholars have claimed that states are constrained by norms of appropriate behavior and furthermore that norms actually change ("reconstitute") states' understandings of their interests, thereby leading states to adapt their behavior in accordance with these new understandings. We test the proposition that norms alter state behavior with respect to the expanding international norm against torture from 1985 through 2003. Unfortunately, we find no evidence that the spreading of the international norm against torture, measured by the percentage of countries in the world that have acceded to the United Nations Convention against Torture, has led to any reduction in torture according to a variety of measures. (c) 2009 by The University of Chicago. All rights reserved..