In the absence of a clear majority, the diversity of social information produces opposite effects on herding behavior and subjective uncertainty

Navajas, Joaquin, Oriane Armand, Bahador Bahrami, and Ophelia Deroy. 2018. “Diversity of Opinions Promotes Herding in Uncertain Crowds.” PsyArXiv. April 5. doi:10.31234/osf.io/mvy25

Abstract: Classic and recent studies demonstrate how we fall for the ‘tyranny of the majority’ and follow the dominant trend, perhaps wisely, when uncertain. In many social interactions, however, there is no clearly identified majority, and aggregating the various opinions of others is non-trivial. We asked whether in such conditions herding behavior depends on statistical properties of social information, namely, the variance of opinions in a group. Participants privately estimated the price of eight anonymous paintings. Then, in groups of five, they discussed and agreed on a shared estimate for four paintings. Finally, they provided revised individual estimates for all paintings. We observed that groups converged to each other and boosted their confidence. However, the more diverse groups herded more and showed less confidence. These findings suggest that, in the absence of a clear majority, the diversity of social information produces opposite effects on herding behavior and subjective uncertainty.