From The Wisdom of Crowds by James Suroweicki:
Sometimes when a group deliberates, extreme positions become less extreme (i.e. moderates).
Frequently, however, deliberation does not moderate but rather radicalizes people’s point of view. This phenomenon is called group polarization. Here are some examples:
- If a group is made up of people who are generally risk averse, discussion makes the group even more cautious
- Groups of risk takers find themselves advocating riskier positions
- People with a pessimistic view of the future become even more pessimistic after deliberations
- Civil juries that are inclined to give large awards to plaintiffs generally give even larger awards after talking it over
As a general rule, discussions tend to move both the group as a whole and the individuals within it toward more extreme positions.