Groupthink is a phenomenon in which a group exerts extensive pressure on an individual to align his or her opinion with other’s opinions.
Groupthink is the tendency of highly cohesive groups to assume that their decisions can’t be wrong: that all members must support the group’s decision and ignore information contrary to it.
George Orwell’s term for the totalitarian imposition of authorized thoughts on all the members of a society is called groupthink. Taken over by some social psychologists interested in the way that members of very cohesive groups can become so preoccupied with maintaining a group consensus of thought that their critical faculties become dulled.