Extremists are often following one another.

If a group is embarking on an unfortunate course of action, a single dissenter might be able to turn it around, by energizing ambivalent group members who would otherwise follow the crowd.

Indeed, unjustified extremism frequently results from a “crippled epistemology,” in which extremists react to a small subset of relevant information, coming mostly from one another.

This finding suggests that people did not really believe their own senses were misleading them; they were trying instead not to look stupid in front of other people.

But other people, though believing that group members were unaccountably mistaken, were unwilling to make, in public, what those members would see as an error.

In a well-functioning democracy, institutions reduce the risks that accompany conformity, in part because they ensure that conformists will see and learn from dissenters, and hence increase the likelihood that more information will emerge, to the benefit of all. A high-level official during World War II attributed the successes of the Allies, and