Trace how groupthink produces a decision nobody would have made alone. Put the steps in causal order.

1. A highly cohesive group works under pressure to reach agreement quickly.
2. Members who have doubts keep them to themselves rather than disturb the harmony.
3. The resulting silence is read as agreement, producing an illusion of unanimity.
4. Feeling unanimous and invulnerable, the group stops seriously appraising alternatives.
5. A decision is reached that no individual member would have made on their own.

The sequence explains the paradox: each individual step is reasonable, and the group's cohesion is normally an asset. Self-censored doubts create false unanimity, false unanimity creates over-confidence, and over-confidence removes the appraisal that would have caught the error - which is why the remedies all consist of forcing dissent back into the room.