IQ is an obvious answer, but what about the 200iq genius who's never fixed his car? Or the illiterate, but skilled mechanic? What defines a "genius" to you? There are geniuses within music, but there are also geniuses within science, but a scientist would make a lousy musician and a musician would make a shit scientist.
I guess what I'm getting at is if there's a line between genius and stupid, where does it exist? Is Peyton Manning not a genius in regards to throwing a football? Is Mozart not a genius when it comes to composition? And is intelligence required to be a genius?