Pluralistic ignorance
In social psychology, pluralistic ignorance is a situation in which a majority of group members privately reject a norm, but go along with it because they incorrectly assume that most others accept it. This is also described as "no one believes, but everyone thinks that everyone believes". In short, pluralistic ignorance is a bias about a social group, held by the members of that social group.
Media pluralism
Media pluralism defines the state of having a plurality of voices, opinions and analyses on media system (internal pluralism) or the coexistence of different and diverse types of medias and media support (external pluralism).