Group Extremity
Interesting insight into group dynamics from a book called Risk by Dan Gardner (who I hadn’t heard of, but his blog looks pretty good).
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 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.
Groups rile themselves up. Makes sense in the face of angry mobs, but hadn’t thought about it in this context before.

Hi, I'm 
holy guac this is the third post of yours I comment on in the last 14.982 mins. oy. anyways, I think Surowiecki refers to this in The Wisdom of Crowds. when birds of a feather flock together, you get more extreme sentiment than that of any individual bird in the group. hence one of the requirements for crowd wisdom to emerge being diversity of opinion (http://en.wikipedia.org/wiki/The_Wisdom_of_Crowds#Four_elements_required_to_form_a_wise_crowd).
Do you think this translates well into positive sentiments as well though? I think there are more people who want to be the anti-cool than want to be the anti-dangerous :)