We laugh at all sorts of things besides jokes. The most popular explanation is that laughter arises from the perception of incongruity. Maybe so, but I think there is more to be said.
In the first place, some incongruities are more laughable than others. Have you noticed how much laughter arises just from the mismatch of level – from incongruity between the glorious and the base, the lofty and the low?
For instance, someone may laugh because things turn out to be more wonderful than he had expected: “When the Lord restored the fortunes of Zion, we were like those who dream. Then our mouth was filled with laughter, and our tongue with shouts of joy.” On the other hand, someone lofty may laugh because of the follies of those beneath him: “Why do the nations conspire, and the peoples plot in vain? ... He who sits in the heavens laughs; the Lord has them in derision.”
Congruities and incongruities also come in layers. The laughing cynic says “That was worse than I expected – but after all, I expect to find things worse than I expected!”
Yet I’m not convinced that even layered incongruity catches all of the causes of laughter. For don’t we sometimes laugh from bleak bitterness? “Just as I thought, there’s no justice!” Or from sheer exaltation? “It’s just as lovely as I had expected!” Laughter of these kinds seems to erupt from the perception of congruity, not of incongruity – from a match, not a miss.
Back to the drawing board.
In the meantime, as to you cavilers, carpers, and crabs of condescension who ask, “Doesn’t it miss the point of laughter to theorize about it?” To you I say, “Ha!”