Social norms help to solve collective dilemmas. In addition to the internalization of norms, social control, rational calculation, and rational acceptance, this paper analyzes the role of information in regard to compliance with norms. We predict that people will cooperate if they believe that others will cooperate as well, and that they will defect if they believe that others will defect. Each reaction respresents a rational course of action. Beliefs about the validity of norms are influenced by information, whether public (as obtained from the media) or private (gained from personal experience), with which individuals update their beliefs. Complementing existing explanations of norm compliance, this paper studies the effect on norm compliance of information which allows individuals to adjust beliefs about whether a norm is valid. The empirical findings based on a multilevel analysis of survey data from 24 countries strongly confirm the prediction that collectively held beliefs about the validity of norms are a major factor in determining compliance, comparable in its strength to the internalization of norms.