The Economist: What Makes for a Great Prank?

The best pranks have always blurred the lines between legality and illegality, good and bad taste, right and wrong conduct. Festivals like Saturnalia appeared to undermine the social order, but paradoxically helped to reaffirm it, by allowing people to act out their frustrations in a harmless way. The nearest thing to this today is April Fool's Day—“the day we remember what we are the other 364 days of the year,” as Mark Twain gently put it—though the best April 1st jokes tend to be media hoaxes, rather than traditional pranks. A classic of the genre is a 1957 BBC “documentary” on Swiss spaghetti farmers. Many British viewers asked where they could buy pasta trees.