B. F. Skinner (1904-1990), an American psychologist, and Jean Piaget (1896-1980), a Swiss psychologist, were two of the most influential human development theorists of the twentieth century. The two men approached the question of development from very different angles. Skinner, a behaviorist, worked from a learning perspective and saw human development as a continuous process in which changes in behavior were responses to experience and adaptation to the environment. Piaget, on the other hand, took a cognitive approach and was concerned with the evolution of mental structures. Where Skinner saw development in quantitative terms (i.e., changes in the amount learned), Piaget held that development occurred in stages in which qualitative changes (i.e., changes in how the person thinks) enabled the individual to construct her/his world through progressively more complicated processes. These stages, he proposed, are coordinated with age and are cumulative. Skinner was devoted to the idea that development could and should be the object of rigorous scientific study in which well-designed experiments would provide data on learning mechanisms. But Piaget did little experimental work of this type and, for the most part, relied on careful observation of, at first, his own children. Despite their differing approaches however, Skinner's and Piaget's theories were not entirely mutually exclusive and the study of both approaches contributes to understanding human development.
Skinner and his followers may have overestimated the importance of conditioning--though they clearly demonstrated that it was a major, complex component of learning. And Piaget's original theory may have underestimated children's mental capacities. Yet both men's theories were the basis for much of the research and thinking about development that has taken place since them and their work has been elaborated in, for example, Social-learning, or Social-cognitive, lear...