Measuring Minds: Boring, Skinner, McGregor, and Stevens, and the Origins of Operationism

In 1935, Stanley Smith Stevens published two articles in which he urged for a revolution in psychology. Building on P.W. Bridgman’s methodological prescriptions for physicists, Stevens argued that all psychological concepts need to be strictly defined in terms of public operations. If psychology is to be taken seriously as a rigorous science, Stevens argued, psychologists have to make sure that they are not talking at cross purposes when they are discussing their theories about ‘experience’, ‘consciousness’, and ‘sensation’, they have to make sure that their concepts are ‘operationally defined’. In view of Stevens’ success in spreading the operationist message, it is small wonder that he is widely viewed as the intellectual father of psychological operationism. In this paper, however, I argue that Stevens was not the first scholar to translate Bridgman’s conceptual strictures to psychology. I show (1) that Gary Boring and B.F. Skinner had already been applying Bridgman’s approach to psychology when Stevens was still an undergraduate student and (2) that Douglas McGregor coined the term ‘operationism’ before Stevens. Since Boring, Bridgman,McGregor, Skinner, and Stevens were all affiliated with Harvard in the early 1930s, the question arises what role these scholars played in the development of psychological operationism. In this paper, I answer this question by examining a large set of documents from the Harvard University Archives. Instead of taking Stevens’ papers as the *starting point* of the operationist turn, I reconstruct the intellectual climate at Harvard in the years leading up to the publication of the operationist manifestos.