John B. Watson
The behaviorists shared with their predecessors a philosophical inclination toward positivism and determinism. With Skinner, however, they entered into a line of thought, extending back to Austrian physicist and philosopher Ernst Mach, which held that the research methods most faithful to their scientific orientation would yield "the pursuit of tools for the control of life problems rather than a search for timeless truths". The behaviorists argued that many contents of the mind were not open to scientific scrutiny and that scientific psychology should emphasize the study of observable behavior. Behaviorists focused on behavior–environment relations and analyzed overt and covert (i.e., private) behavior as a function of the organism interacting with its environment. Therefore, they often rejected or deemphasized dualistic explanations such as "mind" or "consciousness"; and, in lieu of probing an "unconscious mind" that underlies unawareness, they spoke of the "contingency-shaped behaviors" in which unawareness becomes outwardly manifest.
Among the behaviorists' most famous creations are Watson's Little Albert experiment, which applied classical conditioning to a human being, and Skinner's notion of operant conditioning, which acknowledged that human agency could affect patterns and cycles of environmental stimuli and behavioral responses. American linguist Noam Chomsky's critique of the behaviorist model of language acquisition is regarded by many as a key factor in the decline of behaviorism's prominence. But Skinner's behaviorism has not died, perhaps in part because it has generated successful practical applications. The fall of behaviorism as an overarching model in psychology, however, gave way to a new dominant paradigm: cognitive approaches.