The Social Psychology of the Wisdom of Crowds (with a New Section on Recent Advances)

This chapter reviews the “wisdom of crowds” through the lens of social psychology. Early research on social influence cast a pessimistic light on whether collectives can be wise. The famous Asch (1955) studies left the impression that collective judgment is easily harmed since individuals conform too readily to what others say. Research on the wisdom of crowds, of course, demonstrates the benefits of collective judgment over individual judgment. This raises the practical question of how and when collectives will be more accurate than individuals. After briefly reviewing social influence research, the chapter describes the basic logic of the wisdom of crowds: Independent errors are more likely to bracket the truth, which cancel each other out when averaged together. The chapter then turns to conditions that foster better individual inputs to collective judgment by ensuring diverse perspectives through group composition and processes that preserve independence. It also discusses the attraction of relying on single experts and the challenges of reliably identifying them. Finally, the chapter reviews research on the degree to which people understand the benefits of listening to others and evidence that they often fail to learn enough from others. The original chapter was published in 2011. The new chapter ends with an update that explores recent work on the benefits of discussion and analytical techniques for finding the more expert members within a crowd.