Social norms can be understood as either 'what most people think and do' or, alternatively, 'what individuals believe most people think and do.' As such, social norms are about what's considered normal or ought to be normal in a given context and situation. Stated differently, norms reflect real or perceived majority opinion and behavior. Social norms exert influence on people's attitudes and behavior. This influence is strongest when individuals are uncertain about the 'right way' to think and/or act. In these situations, people tend to survey their social and physical environments for attitudinal and behavioral cues or consider what they believe others think they should do. While the research literature includes many types of norms and discusses them from various perspectives, the intersection of social psychology and communication provides promising opportunities for increased understanding of the ways in which norms operate on the ground. The reason for this is simple: for norms to exert social influence, and they must be communicated between and among people.