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.
Willful blindness
Willful blindness (sometimes called ignorance of law, willful ignorance or contrived ignorance or Nelsonian knowledge) is a term used in law to describe a situation in which a person seeks to avoid civil or criminal liability for a wrongful act by intentionally keeping himself or herself unaware of facts that would render him or her liable. In "United States v. Jewell", the court held that proof of willful ignorance satisfied the requirement of knowledge as to criminal possession and importation of drugs.