Groupthink

Put smart people in a cohesive group under pressure to agree, and they can collectively reach decisions none of them would have reached alone. That failure is groupthink.

Groupthink, a term coined by Irving Janis, is the tendency of cohesive groups to suppress dissent and converge prematurely on a consensus, prioritising harmony and agreement over critical evaluation. The result is decisions that are worse than the group's members, thinking freely, would have produced.

How cohesion turns dangerous

The irony of groupthink is that the very things that make a group pleasant and united, cohesion, loyalty, a strong leader, shared identity, are what make it vulnerable. Members self-censor doubts to avoid disrupting the consensus; they assume that silence means agreement; they pressure dissenters back into line; and they shield the group from outside information that might unsettle the emerging view. The drive to maintain unanimity overrides the duty to scrutinise.

The symptoms

Janis identified recognisable signs: an illusion of invulnerability and shared morality, collective rationalising away of warnings, stereotyping of outsiders and opponents, direct pressure on dissenters, self-censorship, an illusion of unanimity, and self-appointed mindguards who keep contrary information from the group. When several appear, a group is likely deciding badly while feeling confident and united, which is the dangerous combination.

Designing against it

Because groupthink feeds on unchallenged consensus, the defences deliberately inject dissent. A leader withholding their own view until others have spoken, assigning someone to argue the opposing case, splitting into independent subgroups, inviting genuine outside challenge, and protecting and rewarding the person who raises doubts all work against it. The aim is to make disagreement safe and expected rather than disloyal, so that consensus, when it comes, has been earned rather than assumed.

Groupthink explains how capable people in well-run organisations produce fiascos that look obvious in hindsight, from military disasters to corporate and engineering catastrophes. It is a warning that a comfortable, agreeable, confident meeting is not evidence of a good decision, and may be evidence of the opposite.