Tim Harford writes about how to avoid the “groupthink risk”: the tendency of committees to congeal around a particular point of view, reassured by the fact that everybody agrees with everybody else, and nervous about expressing dissent (highlighted in 1972 by the psychologist Irving Janis in his famous analysis of the Bay of Pigs fiasco).
The risk of committee thinking is that – paradoxically – a group of people may end up considering fewer alternative points of view than a single person.
Irving Janis argued that someone should always play the role of devil’s advocate, and different people should play the role at different times (the Catholic church invented the idea in the late 16th century.)
Experiments showed that if there was a single dissenter in the room, the experimental subject was far more likely to resist social pressure and pick the correct pair of lines. This was true even if the dissenter himself was also wrong. What mattered was that he said something different.