John Broadus Watson was trained in psychology at the University of Chicago under the functionalist, J.R. Angell(Leahey, 1980). Watson was trained in functionalism, but he rejected the ideas of the functionalist and structuralists and founded his own approach to psychology. He felt that it was impossible to study consciousness because only outward behavior could be scientifically understood(Lahey, 1983). Watson's field was animal psychology; he tells us himself that he preferred to work with animals rather than human subjects, and disliked serving as an introspective subject(Leahey, 1980). He was deeply impressed by the first reports of Pavlov's work on conditioning because of its precision and the absence of introspection. Watson also agreed with Pavlov. The importance of conditioning went far beyond salivating dogs, and that most human behavior is learned through classical conditioning(Lahey, 1983). .
Watson proceeded systematically to criticize structuralism. His first criticism was that there was no room in structuralism for animal study, because its focus was entirely on human consciousness. What little animal study was done, he called "absurd", because the researcher was forced to construct his subject's consciousness on the basis of behavioral data and analogies to human consciousness, an approach Watson called "false". Watson also noted that researchers had provided no firm criterion for ascribing consciousness to animals, and that in any case experiments were designed without reference to consciousness in animals. Watson's basic point was that ascribing consciousness to animals is wholly unnecessary-that behavioral data alone is sufficient for scientific work.
Watson clearly sought out to reformulate the method, problems, and goal of psychology. For introspection, he would substitute classical conditioning. For the problems of attention, feeling, thought, and the description of consciousness he would substitute for learning.