The worst-performing clubs were built on affective ties and primarily social; the best-performing clubs had limited social connections and were focused on increasing returns. Dissent was far more frequent in the high-performing clubs. The low performers usually had unanimous votes, with little open debate. Harrington found that the votes in low-performing groups were “cast to build social cohesion rather than make the best financial decision.” In short conformity resulted in significantly lower returns.
Excerpt from: Conformity: The Power of Social Influences by Cass Sunstein