>Humor is a criticism. We laugh at something because it has gone wrong, for
instance, a person behaving like a thing (running into a door - inertia).
You're always so dark, Joe! Humor is also a social rewards mechanism. If I can make you laugh I gain inceased social standing with you. This is the mechanism that promotes the spread of good jokes. Not because of misplaced tragedy or backhanded criticism, but rather because it helps bind us together as cooporative social groups.