Final answer:
John B. Watson's behaviorism was a departure from later behaviorists like B.F. Skinner, focusing solely on environmental determinism and observable behavior, and setting the stage for psychology as an empirical and measurable science.
Step-by-step explanation:
John B. Watson was a pivotal figure in the development of behaviorism, a school of thought focused on observable behavior over internal mental processes. Contrary to later behaviorists like B.F. Skinner, who acknowledged environmental forces but also incorporated the concept of reinforcement and punishment to modify behavior, Watson was more rigid in his approach. Watson's brand of behaviorism placed a strong emphasis on the capacity to control and predict behavior by manipulating environmental variables, virtually excluding any inherent qualities of the organism.
Watson's approach was more radical in its rejection of inner mental states, embracing a form of environmental determinism where he believed that all human behavior was a result of environmental factors. This was a departure from Skinner's later focus on operant conditioning, where Skinner acknowledged the role of reinforcements and punishments without delving into cognitive processes. Watson's legacy in psychology is significant for steering the discipline towards an empirical, measurable science, with less concern for subjective experience, which marked a significant shift from the introspective methods prevalent at the time.