A tight-knit group can talk itself into a decision every member privately doubts

Irving Janis coined 'groupthink' after studying disasters like the Bay of Pigs invasion, where Kennedy's advisors backed a plan several of them secretly thought was reckless. He found that group cohesion and a desire for unanimity can silence dissent so effectively that nobody voices the doubts everyone in the room actually has. The fix, Janis argued, is deliberately assigning someone to challenge the consensus.

— Irving Janis, Victims of Groupthink — Houghton Mifflin, 1972
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