Psychological operationisms at Harvard: Skinner, Boring, and Stevens.

Contemporary discussions about operational definition often hark back to Stanley S. Stevens' classic papers on psychological operationism. Still, he was far from the only psychologist to call for conceptual hygiene. Some of Stevens' direct colleagues at Harvard-most notably B. F. Skinner and E. G. Boring-were also actively applying Bridgman's conceptual strictures to the study of mind and behavior. In this paper, I shed new light on the history of operationism by reconstructing the Harvard debates about operational definition in the years before Stevens published his seminal articles. Building on a large set of archival evidence from the Harvard University Archives, I argue that we can get a more complete understanding of Stevens' contributions if we better grasp the operationisms of his former teachers and direct colleagues at Harvard's Department of Philosophy and Psychology.