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.
Spiral of silence
Individuals use what is described as "an innate ability" or quasi-statistical sense to gauge public opinion. People assume they can sense and figure out what others are thinking.
Pluralistic ignorance may occur in some cases, leading to the minority opinion to be accepted as a norm. Group members may be privately rejecting a norm, but may falsely assume that other group members accept it. This phenomenon may cause a group to hold on to a norm.