Why does it always seem the more intelligent you are, the more arrogant and obnoxious you become as well?

Have you ever noticed that some of the most brilliant people are sometimes really pretentiously horrible. I'm not saying that being ignorant is the way to go, but lately I've come to distance myself from my super-intelligent friends. They always like to tease me when it's uncalled for or make rude gestures to me as if I was a 6-year old child. Is it perhaps that because i'm not as smart as they are that I don't see the "joy" in being a mean and irritating smart-aleck; or is it that one's intellect and ego are completely unrelated?.In my opinion, a high I.Q. shouldn't necessarily give you license to be a bona fide horse's ***.