What is wrong with the emerging situation? We can find a clue in a small experiment in democracy conducted in Colorado in 2005. About 60 US citizens were put into 10 groups. They deliberated on controversial issues, such as whether the US should sign an inter-national treaty to combat global warming and whether states should allow same-sex couples to enter into civil unions. The groups consisted of predominantly either leftwing or rightwing members, with the former drawn from left-of-centre Boulder and the latter from Colorado Springs, which tends to be right of centre. The groups, not mixed, were screened to ensure members conformed to stereotypes. (If people in Boulder liked Vice-President Dick Cheney, they were cordially excused.) People were asked to state their opinions anonymously before and after the group discussion.
In almost every group, people ended up with more extreme positions. The Boulder groups favoured an inter-national treaty to control global warming before discussion; they favoured it far more strongly afterwards. In Colorado Springs, people were neutral on that treaty before discussion; discussion led them to oppose it strongly. Same-sex unions became much more popular in Boulder and less so in Colorado Springs.
Aside from increasing extremism, discussion had another effect: it squelched diversity. Before members talked, many groups displayed internal disagreement. These were greatly reduced: discussion widened the rift between Boulder and Colorado Springs
Countless versions of this experiment are carried out online every day. The result is group polarisation, which occurs when like-minded people speak together and end up in a more extreme position in line with their original inclinations.
