The value of a lone dissenter

People will often abandon their opinions to conform to what a group expects of them, but a lone voice of reason can save the day. Cass Sunstein’s new book, Why Societies Need Dissent, reports the following (see chapter one):

You can give people a problem and allow them to solve it. Also give them a group of confederates, who unanimously advocate the wrong answer to the same problem. One confederate, proclaiming the wrong answer, will have little influence on the problem solver. Two confederates increased errors to 13.6 percent. Using three confederates increased errors to 31.8 percent. Under some results, more than three confederates do not increase the error rate, although this is controversial. But putting one voice of sanity in the group, who knows and proclaims the right answer, makes a big difference. “Conformity errors” were reduced by an average of three quarters, even if a strong majority of the group leaned the other way. Sunstein draws upon the work of Robert Baron, at the University of Iowa.