I propose that young children may be a useful test case for Fitouchi et al.'s theory that certain seemingly harmless acts are moralized because they are seen as risk factors for future poor cooperation. The theory predicts that prior to the development of certain folk-psychological beliefs about self-control, children should be untroubled by violations of puritanical morality, and that an adult-like folk psychology of self-control should develop in tandem with disapproval of such violations.