I've just caught up with a great article written by social software specialist Clay Shirky on how and why groups behave the way they do online, drawing a bit on face-to-face (well, psychologist W. R. Brion studying neurotics). You'll have to read the article to find just why groups are their own worst enemy, and stay to the end to find Clay's three things to accept in developing or using social software (lists, forums etc) :
1 You cannot separate social and technical discussion
2 Group members are different from users, and you need a core group
3 The core group has rights that trump individual rights in some circumstances - you need governance.
There are also four things to design for in large groups: 'handles' people can invest in (sort of identity); recognition for members of good standing; barriers to participation; and a way to spare the group from scale (too big).
Clay says he writes about “Systems where vested interests lose out to innovation” ... or maybe “Systems where having good participants produces better results than having good planners.” You can read Clay's articles here and subscribe to his mailing list here.
Further thoughts on The Unspoken of Groups by David Weinberger