Altruism constitutes a paradox for learning theory. By definition altruism is a form of behavior which is engaged at some cost to the actor and without tangible rewards for him. Learning theory, however, implicates reinforcement both in the learning and the maintenance of all behavior. How then is altruistic behavior learned and maintained? The roles of affect, cognition, and possibly self-reinforcement are examined for their influence in establishing and maintaining altruistic behavior. The implications of these variables for theories of learning are considered.