 Cass Sunstein reports that introverts can sometimes be silent in meetings with extroverts; he recommends explicitly asking for each person's opinion, either during the meeting or afterwards in one-on-one sessions.Sunstein points to studies showing groups with a high level of internal socialization and happy talk are more prone to bad investment decisions due to groupthink, compared with groups of investors who are relative strangers and more willing to be argumentative.To avoid group polarization, where discussion with like-minded people drives an outcome further to an extreme than any of the individuals favored before the discussion, he recommends creating heterogeneous groups which contain people with different points of view.