Anther article that guy links to is http://paulgraham.com/nerds.html which struck a chord with me. When you are in school intelectualism is actively discouraged by extreme peer pressure from all the other kids. What Paul says is that Nerds are just thinking at a higher age level and as such dont have the time to deal with the mental burden of social conformism as well. When you get to a certian age then it all evens out a bit so the distinction dissapears.
Oops. Sorry for the repost. :(