Young children endorse fairness norms related to sharing, but often act in contradiction to
those norms when given a chance to share. Thus, young children appear to be moral hypocrites with
regard to fairness. Moral hypocrisy refers to the failure to follow one’s own expressed moral rules and
principles. Moral hypocrisy of children mainly involves two forms: “knowledge-behavior gap” and “double
standard”. Knowledge-behavior gap is the intrapersonal discrepancy between what individuals think
is normative and how they actually behave. Double standard focuses on the tendency among people to
judge others more severely than they judge themselves. At present, the explanation of the mechanism of
moral hypocrisy mainly emphasizes four viewpoints: The viewpoint of insufficient motivation hypothesis,
the viewpoint of insufficient cognitive resources hypothesis, the viewpoint of social signal model, and the
viewpoint of social learning theory. Future researchers can pay attention to how family and environment
affect children’s moral hypocrisy, and provide theoretical support for the intervention and prevention of
moral hypocrisy.