http://www.cornellsun.com/vnews/display.v/ART/2004/12/02/41ae87066c10f
I say with a fair degree of certainty that I have personally met more wikipedians than any other person.
And I have yet to meet people who fit the descriptions he gives in the article. Wikipedians are really smart people typically, but also very friendly and outgoing. Because of the essentially social nature of how we work together, success in the wikipedia community depends on having good social skills as well as having intelligence
(Of course I suppose the more shy among us may tend to avoid the meetups. People can be socially skillful online, but still shy about coming out to meet people. For those who feel this way, I recommend to try it sometime, you'll find out that you like them as much in person as you do online. :-))
--Jimbo