Several theoretical approaches have been used to address whether there is a causal connection between reasoning and behavior, whether reasoning is a person variable or a product of the social environment, whether reasoning is related to particular contexts, and what basic psychological and social processes underlie the use and effects of reasoning. These theoretical approaches include cognitive developmental theory, differential association theory, social relations theory, attribution theory, and theories about the links between beliefs/values and behaviors. In considering limitations of cognitive and social learning models, the author indicates the social learning model appears to be a step in the right direction because it shores up the weaknesses of the cognitive model. As a learning theory, however, it tends to ignore reasoning in favor of its underlying behavior, verbalization. The importance of the social context and role taking in formulation of reasoning by children and youth is emphasized, and the potential of a social process explanation of reasoning is discussed. Further research on actual interchanges that occur within group deliberation processes is recommended in order to develop a better theoretical understanding of peer influences on the formation and use of reasoning by young people. 52 references