How can we change social norms, the standards describing typical or desirable behavior? Because individuals’ perceptions of norms guide their personal behavior, influencing these perceptions is one way to create social change. And yet individuals do not form perceptions of typical or desirable behavior in an unbiased manner. Individuals attend to select sources of normative information, and their resulting perceptions rarely match actual rates of behavior in their environment. Thus, changing social norms requires an understanding of how individuals perceive norms in the first place. We describe three sources of information that people use to understand norms—individual behavior, summary information about a group, and institutional signals. Social change interventions have used each source to influence perceived norms and behaviors, including recycling, intimate‐partner violence, and peer harassment. We discuss conditions under which influence over perceived norms is likely to be stronger, based on the source of the normative information and individuals’ relationship to the source. Finally, we point to future research and suggest when it is most appropriate to use a norm change strategy in the interest of behavior and social change.