Cohesiveness is a desirable goal, but challenge and confrontation are inevitable occurrences in a healthy team. In groupthink, all three elements take an unhealthy detour in the course of team development. Cohesiveness becomes narrowly defined as all-important agreement while challenge and confrontation are interpreted as member disloyalty and are avoided. A team continues on an unhealthy path when its close-mindedness to diversity of opinion spreads from inside to outside the group, increasing team isolation. It is during this stage of groupthink that a team is most apt to act on its unquestioned, inappropriate ideas in an effort to maintain group cohesiveness and solidarity.
Groupthink creates havoc.
Evidence of such can be found in a variety of teams of historical significance. Janis 2 and others have documented the phenomenon in the Bay of Pigs, Watergate, and Pearl Harbor. Some answers are found in the classic psychological studies of the perception process. For example, Burke demonstrated that when presented with a simple bar graph on a page, individuals will more often than not say that the bars are of equal length if their peers have proclaimed them to be so, even though when measured, one bar is clearly longer than the others. This phenomenon, called cognitive dissonance, has important implications for teams.