Sometimes, when you have a highly-cohesive group, people will publicly support ideas that others in the group champion while harboring private reservations about them simply not to ‘rock the boat.’

This can lead to poor decision making.

Examples of Groupthink:

• US in Vietnam
• US Navy’s complacency ahead of Pearl Harbor
• President Kennedy’s Bay of Pigs Invasion

Groupthink: A Mode of thinking that people engage in when they are deeply involved in a cohesive in-group, when the members’ striving for unanimity override their motivation to realistically appraise alternative courses of action.” – Irving Janis.

Symptoms of Groupthink

• Illusion of invulnerability.
• Belief in inherent morality.
• Collective rationalization.
• Refusing to accept outside ideas or vet them thoroughly.
• Stereotyping those outside of the group and not examining others or their ideas closely.
• Self-censorship.
• Illusion of unanimous behavior. Not testing the group to see how much consensus there really is.
• Pressuring group members who do not agree.