Abstract
This article reflects on the oddness of humor and laughter as human behaviors. It argues against classifying humorous amusement as an emotion by contrasting amusement with standard emotions. It then examines amusement as a kind of pleasure, specifically, the enjoyment of psychological shifts. It argues that humor evolved from mock-aggressive play in pre-human apes, with laughter serving as a play signal. Understanding humor as play not only helps explain laughter but also clarifies issues in the ethics of humor, such as the wrongness of racist and sexist jokes, and the question of whether a sense of humor is a virtue.