https://en.wikipedia.org/wiki/Pluralistic_ignorance

In social psychology, pluralistic ignorance (also known as a collective illusion)[3] is a phenomenon which occurs when people mistakenly believe that everyone else holds a different opinion than their own.[4] Most people in a group may go along with a view they do not agree with, because they incorrectly think that most other people in the group agree with it. It refers to a situation in which the minority position on a given topic is wrongly perceived to be the majority position or where the majority position is wrongly perceived to be the minority position.[5][6] Pluralistic ignorance can arise due to a number of different factors. An individual may misjudge overall perceptions of a topic due to fear, embarrassment, social desirability, or social inhibition. Any of these can lead to the individual incorrectly perceiving the proportion of the general public who share similar beliefs to oneself. As such, pluralistic ignorance can only describe the coincidence of a belief with inaccurate perceptions, but not the process to get to those inaccurate perceptions. Thus, individuals may develop collective illusions when they feel they will receive backlash on their belief as they think it differs from society’s belief.[7]