Groupthink is a mode of thinking that people engage in when they are deeply involved in a cohesive in-group, when the members' strivings for unanimity override their motivation to realistically appraise alternative courses of action. There are several symptoms of groupthink. Members believe in the morality of their own group. They hold shared stereotypes of outsiders. Problems are dismissed with collective rationalization.
Doubts are self-censored so that an illusion of unanimity occurs.
By assigning members to act as devil's advocates and by holding second chance meetings, members can guard against groupthink. Groups go through identifiable phases. Using zero-history LGDs, researchers have mapped stages in the life of a group. C. Fisher found four phases. In the conflict phase, members experience secondary tension as they disagree about task and struggle to define leadership roles.