In this article, we will look at the influence which Bridgman's philosophy of operationalism had on the discipline of psychology. Associated as it is among philosophers with logical positivism, it is perhaps unsurprising that it was the logical positivist Herbert Feigl who introduced the behaviorists of the 1930s to the philosophy. Among psychologists, operationalism became known as "operationalism"(Green, 1992).
One of the most popular operationist sentiments in psychology was that enunciated by E.G. Boring in 1923, when he commented in an article on intelligence tests that "intelligence is what the [intelligence] tests test." Indeed, intelligence is a kind of operational construct. Since this is so, why should its particular operational definition as IQ be preferred over other constructs? Because IQ tests exhibit extremely high levels of both technical reliability and validity, and are highly correlated with certain kinds of social and individual outcomes and specific neurobiological correlates.
Eventually, operationism became the standard form of empiricism among psychologists. First, let us look at the psychological operationism of Edward C. Tolman. Once again, the influence of the logical positivists upon the development of operationism is quickly evident. Tolman met Moritz Schlick in the early 1930s, the founder of the logical positivist group the 'Vienna Circle' himself. Edward Tolman was so impressed by Bridgman's operationalism that he began referring to himself as an operational behaviorist(Green, 1992).
A behaviorist, Tolman seems to have initially wanted to press Bridgman's operationalism into the service of the eliminativist metaphysics typical of his ideology. Words like "cognition" and "purpose" referred to mere behavior-gestalts rather than mental entities. They were "functional" labels defined purely in terms of operational measures of outward behavior(Green, 1992).
Eventually, however, Tolman conceded that mental entities must exist. In this respect, he began to depart from orthodox behaviorism, referring to mental entities as "intervening variables." Indeed, at one point he conceded the propriety of Köhler's amusing reference to Tolman as a "cryptophenomenologist"(Green, 1992).
Bridgman wanted to get rid of all metaphysical concepts and utterly replace them with operations. It would appear, then, although Bridgman may have objected to this, that the consistent behaviorist must be an eliminativist and reject the existence of mental entities. Instead, Tolman ended up as a kind of phenomenologist who simply wanted to apply operations in the measurement of metaphysical concepts(Green, 1992).
Thus, to measure Felipe's love of chow chows is not to define Felipe's love of chow chows in terms of the behavioral manifestation thereof, which involves petting chow chows. Instead, the latter behavior is simply a measure of it, but not a reduction of it to that measure. It is an indirect measure of the manifestation of a metaphysical concept rather than its definition.
While this is an inversion of operationalism, it may solve some of its problems. There are a potentially infinite number of ways, presumably, to measure Felipe's love of chow chows. From the operationalist perspective, this would result in the disturbing conclusion that there are an infinite number of definitions of Felipe's love of chow chows, rather than merely an infinite number of indirect measurements of the phenomenon, each of which may correlate more or less with certain predictions we might want to make in relation to this concept and its measurements(Green, 1992).
The question which measurement is best, then, simply becomse a question of which measurement most faithfully and accurately measures the actual extent to which Felipe loves chow chows. But is this operationalism at all? Indeed, it is a rejection of operationalism since these indirect measurements are not true operational definitions from Bridgman's perspective at all. They are simply indirect measurements of something, and therefore, pre-operationalist measurements. We end up with a quite unremarkable and decidedly non-operationalist means of measurement (for better or worse)(Green, 1992).
B.F. Skinner, of course, took operationalism to its eliminativist conclusion. He saw psychology as beset with clumsy terminology in need of revision which left psychology in an unscientific mire. Thus, he was no fan of Tolman's 'operationism.'
The next operationist psychologist we will look at is S.S. Stevens. What made Stevens unique was his assertion that not all operations were created equal. Instead, there was a hierarchy of operations(Green, 1992). This was closely linked with his idea that the fundamental and most basic operation was that of discrimination. For example, while two operationist psychologists might not agree that Felipe is excited about the fact that chow chows have squishy faces, they can at least agree that something about chow chows causes Felipe to be excited. If they cannot agree on that, they can at least agree that Felipe tends to pet chow chows. They can continue to move on down to more and more obviously true observable facts about Felipe's relation to chow chows.
Green, Christopher (1992). Of Immortal Mythological Beasts: Operationism in Psychology. Retrieved from: http://philsci-archive.pitt.edu/199/1/operat.htm. Theory & Psychology, 2, 291-320.