This paper describes a program of research into children's understanding of psychological principles underlying social behavior. An initial study had indicated that at about 10 years of age children knew many of the basic principles of social behavior and the rules for social control. Two strategies were developed to explore these findings in depth. In the first, an attempt was made to identify objective conditions that make self-regulation (delay of gratification and resistance to temptation) either difficult or easy. In the second, the individual's own developing understanding of effective strategies for self-regulation, such as plans, was explored. Among preschool children the ability to delay gratification was found to be enhanced when delayed rewards were not in view. It was further found that the effect of the presence or absence of rewards could be overcome by changing how the child ideationally represented those rewards during the delay period. In experimental situations, children's spontaneous delay strategies showed a clear developmental progression in knowledge of effective delay rules. It is noted that the same progression has been found in explorations of self-control situations in everyday life. By age 10, some children seemed to have well developed ideas about the nature, organization and function of plans (including plans for self-regulation) in their own lives. (Author/RH)