Diversity and groupthink

Nate Silver’s talk at the Joint Statistical Meetings a couple of weeks ago identified groupthink by insiders as a major threat to accurate journalism.  It’s natural to believe the opinions of other intelligent, well-informed people, but if they are working from  the same limited set of information as you, the fact that they agree with you is not actually good evidence that you’re right.

Tim Harford has a column this week arguing that diversity is important, for basically this reason. Even if, say, women or Maori or Asians or small-town farm boys aren’t actually better at decision-making, the simple fact that they have different starting points can lead to better decision-making by groups. It doesn’t have to, but it can. The New York Times also has a piece on this theme, by political scientist Scott Page.

An important empirical basis for the idea that diversity is, in itself, beneficial is the work of Solomon Asch on conformity.  Asch found that even in very simple decisions, many people would follow an obviously-wrong choice made by enough other people. On the other hand, even a single non-conforming voice, and even one that was more wrong than the consensus, could free people to follow the evidence of their own eyes.