140 characters to groupthink
In the various “echo chambers”, where people retweet each other, send each other links supporting their common beliefs, and support each other against common enemies, 140 characters is enough. In contrast, delving into differences of fact or interpretation or opinion generally requires more space than that. So Twitter sucks for any kind of meaningful discussion.
Furthermore, Twitter makes it easy to stick with members of your own tribe and nobody else. Groupthink forms easily when nobody outside the group is present, and then any form of negativity or skepticism or disagreement is frowned on. Meanwhile, existing beliefs common to the group get plenty of reinforcement.
On Twitter, how often does anyone’s mind get changed about anything? I suspect that the answer is “not very often”.
My March 2007 blog post about Twitter, Reduced barriers to entry for ... narcissism!, was off the mark (I don’t mind admitting it since so many others were wrong too). Perhaps the real downside of Twitter is that it contributes not to narcissism but to rigidity. Mob psychology among people who aren’t even in the same place; just what the world needs.