Irving Janis

American psychologist

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July 20, 2026

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Irving Janis was an American psychologist who developed the theory of groupthink. This is a mode of thinking where members of a cohesive group tend to accept a viewpoint that represents a perceived group consensus, even if they don't believe it's valid. Groupthink hinders effective problem-solving and can lead to poor decisions, even among intelligent individuals. Janis identified several conditions that contribute to groupthink, including group cohesiveness, leadership style, and participant homogeneity. Symptoms include an illusion of invulnerability, rationalization of decisions, stereotyping opponents, and self-censorship. This theory has been applied to various fields, including social psychology and foreign policy analysis.12

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groupthink
…developed by the social psychologist Irving Janis in his classic 1972 study, Victims of Groupthink: A Psychological Study of Foreign-Policy Decisions and Fiascoes, which focused on the psychological mechanism behind foreign policy decisions such as the Pearl Harbor bombing, the Vietnam War, and the Bay of Pigs invasion.
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…developed by the social psychologist Irving Janis in his classic 1972 study, Victims of Groupthink: A Psychological Study of Foreign-Policy Decisions and Fiascoes, which focused on the psychological mechanism behind foreign policy decisions such as the Pearl Harbor bombing, the Vietnam War, and the Bay of Pigs invasion.
Read More