Groupthink
Groupthink is a psychological phenomenon, identified by the social psychologist Irving L. Janis, to describe the behavior of people within a group whose desire to minimize conflict and to achieve a consensus causes them to prioritize conformity and uniformity over critical thinking ("hive mind"), and individual evaluation, beliefs, and opinions in order to avoid controversy, criticism, and isolation. Members of the group, or collective, may choose to passively agree or actively suppress opposition.
Example:
Even though Mary’s personal experience in the medical profession caused her to doubt that the opinion of the majority of the members of the committee she did not feel comfortable voicing her opposition to the plan.
See Collectivism, Hegelian Utopia, Progressivism, Socialism, and Communism