Maybe the difference is more thus.
Genius and insanity: We got warned in training that very intelligent people on certain tests can score very similarly to people who suffer from psychotic disorders. Why? different ways of seeing reality. This is why it is imperative that one does not diagnose a patient based on pencil and paper measures only. People who are very intelligent and suffer from disorders seldom leap without looking. Often they have a good idea of what the consequences of leaping are and have taken them into account, albeit more quickly or in a manner that is unlike that of most people. They often are less quiet about making the leap than are "sane " genuises and offend people while leaping. I think this is what can get them into trouble

Insanity and stupidity: these are the guys who don't look before leaping. We just never hear about these guys. These are the ones who tie the rockets on their backs thinking they're going to get to the moon and everyone says "Go figure". Sometimes they get lucky and really stop and think and do something great. More power to them, I say! I don't think you have to be that insane to fit into this group. Sometimes it's just the guy who ends up impulsively saving the lives of several other people because the idea suddenly hits him to try something no one else ever has, but he doesn't know that. He just doesn't have anything left to lose...