They score higher than normal on a number of psychotic measures--in yet another link between creativity and madness.
It's almost the job of a comedian to leave you thinking that he or she is a little off in the head. Take the Curb Your Enthusiasm episode where a Survivor contestant argues with a Holocaust survivor about who's the tougher survivor. Or Dave Chappelle portraying Clayton Bigsby, the blind, white supremacist who doesn't realize he's black. Or Louis C.K. entertaining the idea that maybe everyone with a peanut allergy is actually supposed to die. Or pretty much anything Sarah Silverman has ever said.