Cass R. Sunstein, Infotopia: How Many Minds Produce Knowledge (Oxford 2006) at 55, discusses research about the shortcomings of groups when they deliberate. For example, members tend to become much more confident about their judgments after they talk together, but they are not any more likely to be correct. Second, “deliberation usually promotes uniformity by decreasing the range of views within groups.” Broadly, Sunstein states that “It cannot be shown that deliberating groups generally arrive at the truth” (at 57). Worse, they “do quite poorly at aggregating the information that their members have” (id).
Many readers of this blog may believe it unquestionable that a group improves on an individual when the group makes a decision. Well, question it, as perhaps it is an urban myth of social psychology. This contrary view is something like brainstorming shown to be less than touted (See my post of Dec. 31, 2008: problems with brainstorming.), or diversity in a group giving it headaches (See my post of May 26, 2010: heterogeneity may adversely affect teams.), or smart people not being more creative (See my post of March 21, 2011: no correlation of IQ and creativity.), or committees often stumbling (See my post of Aug. 28, 2006: attack on committee effectiveness.). Common beliefs may be wrong.