As observed by Aldag and Fuller (1993), the groupthink phenomenon seems to rest on a set of unstated and generally restrictive assumptions:

The purpose of group problem solving is mainly to improve decision qualityGroup problem solving is considered a rational process.Benefits of group problem solving:variety of perspectivesmore information about possible alternativesbetter decision reliabilitydampening of biasessocial presence effectsGroupthink prevents these benefits due to structural faults and provocative situational context.Groupthink prevention methods will produce better decisionsAn illusion of well-being is presumed to be inherently dysfunctional.Group pressures towards consensus lead to concurrence-seeking tendencies.

According to Janis, decision-making groups are not necessarily destined to groupthink. He devised ways of preventing groupthink:

Leaders should assign each member the role of "critical evaluator." This allows each member to freely air objections and doubts.Leaders should not express an opinion when assigning a task to a group.Leaders should absent themselves from many group meetings to avoid excessively influencing the outcome.The organization should set up several independent groups working on the same problem.All effective alternatives should be examined.Each member should discuss the group's ideas with trusted people outside of the group.The group should invite outside experts into meetings. Group members should be allowed to discuss with and question the outside experts.At least one group member should be assigned the role of devil's advocate. This should be a different person for each meeting.