Somewhere I picked the notion that the evolutionary basis (value) of humor is stepping outside rigid responses. (This may have been from Hofstadter.) A clown is someone who is *playing the fool*.

So: the moment of broading your own insight is enjoyable. More importantly, so is pointing out where someone else *doesn't* have insight. And then everyone else laughs too. So it's a way for the group to rein in idiots -- even if (especially if) the idiot is the tribe leader or elder.

(This theory is more than six years old, honest...)