Final answer:
John Watson, Ivan Pavlov, and B.F. Skinner, all associated with behaviorism, emphasized that psychology is the scientific study of observable behavior, moving away from the study of inner mental processes.
Step-by-step explanation:
The psychologists John Watson, Ivan Pavlov, and B.F. Skinner were all proponents of the behaviorist approach to psychology. They would have agreed that psychology is the study of observable behavior. Behaviorism, as a school of thought, focuses on objective, observable behaviors rather than on unobservable mental states or cognitive processes. Whereas earlier psychologists and schools of thought such as structuralism and Freudian psychoanalysis John Watson, Ivan Pavlov, and B.F. Skinner would have agreed that psychology is concerned with the inner workings of the mind, behaviorists like Watson, Pavlov, and Skinner argued that psychology should be a science of observable behavior because it can be objectively measured and studied.