Just a Gwai Lo fun within prescribed limits [?]

Jim Holt: “Although we think of the joke as a cultural constant, it is a form of humor that comes and goes with the rise and fall of civilizations. What distinguishes the joke from the mere humorous tale is that it climaxes in a punch line—a little verbal explosion set off by a sudden switch in meaning. A joke, unlike a tale, wants to be brief. As Freud observed, it says what it has to say not just in few words but in too few words. The classic joke proceeds with arrowlike swiftness, resolving its matter in the form of a two-liner (“Hear about the bulimic stag party? The cake came out of the girl”) or even a one-liner (“I was so ugly when I was born, the doctor slapped my mother”). Often, it is signalled by a formulaic setup, which might itself, in turn, become the subject of a meta-joke (“A priest, a rabbi, and a minister walk into a bar. Bartender says, ‘What is this, a joke?’ ”).”

David Meadows highlights the classics' angle, and has links to more ancient humour resources.