Pluralistic ignorance begins with a discrepancy between public actions and private sentiments, typically produced by widespread behavioral adherence to a social norm. Pluralistic ignorance is a pervasive feature of social life and is found to characterize the dynamics of social situations, social groups, and social movements. Group identification is the root cause for many cases of pluralistic ignorance—that individuals often act out of a desire to be good group members but interpret others’ similarly motivated behavior as reflecting personal beliefs and opinions. This chapter presents two cases of pluralistic ignorance: (1) concerning the attitudes of college students toward alcohol use on campus and (2) concerning the gender stereotypes held by elementary school children. Mean responses of students in percentage are graphically represented in the chapter. Pluralistic ignorance describes the case in which virtually every member of a group or society privately rejects a belief, opinion, or practice, yet believes that virtually every other member privately accepts it. The term “pluralistic ignorance” is something of a misnomer, for in these cases, group members are not, in fact, ignorant of one another’s private sentiments; rather, they think they know, but are mistaken.