But they won’t. Decades of research has proved that groups usually come to conclusions that are more extreme than the average view of the individuals who make up the group. When opponents of a hazardous waste site gather to talk about it, they will become convinced the site is more dangerous than they originally believed. When a woman who believes breast implants are a threat gets together with women who feel the same way, she and all the women in the meeting are likely to leave believing they had previously underestimated the danger. The dynamic is always the same. It doesn’t matter what the subject under discussion is. It doesn’t matter what the particular views are. When like-minded people get together and talk, their existing views tend to become more extreme.
In part, this strange human foible stems from our tendency to judge ourselves by comparison with others. When we get together in a group of like-minded people, what we share is an opinion that we all believe to be correct and so we compare ourselves with others in the group by asking ‘How correct am I?’ Inevitably, most people in the group will discover that they do not hold the most extreme opinion, which suggests they are less correct, less virtuous, than others. And so they become more extreme. Psychologists confirmed this theory when they put people in groups and had them state their views without providing reasons why – and polarization still followed.
Excerpt from: Risk: The Science and Politics of Fear by Dan Gardner