Evolutionary theory in Freud, Piaget, and skinner

This essay traces the roots of evolutionary concepts in modern psychology, as found in the theories of the shapers of three of its major schools of thought: Freudianism, Genetic Developmentalism, and Behaviorism. All three theorists differed from most of their colleagues in acknowledging the fact of organic evolution, as well as the universal applicability and priority of the scientific process. All three sought to continue the Copernican?Darwinian conceptual revolution by building a unified general theory capable of explaining not only organic change, but individual development and cultural evolution as well. They differed, however, as to the nature of the mechanism driving the process. For Freud it was the sex drive; for Piaget, the internal sensation of disequilibrium; and for Skinner it was environmental reinforcement functioning according to the principle of natural selection. Any future paradigm for the social sciences will no doubt be generated from some combination of these models.