THE EXPERIMENTAL ANALYSIS OF OPERANT BEHAVIOR

I was drawn to psychology and particularly t o behaviorism by some papers which Bertrand Russell published in the Dial in the 1920s and which led me t o his book Philosophy1 (called in England An Outline of Philosophy), the first section of which contains a much more sophisticated discussion of several epistemological issues raised by behaviorism than anything of John B. Watson’s. Naturally, I turned t o Watson himself, but a t the time only t o his popular Behaviorism.2 I bought Pavlov’s Conditioned Relfexess shortly after it appeared, and when I came t o Harvard for graduate study in psychology, I took a course that covered not only conditioned reflexes but the postural and locomotor reflexes of Magnus and the spinal reflexes reported in Sherrington’s Integrative Action of the Nervous System.4 The course was taught by Hudson Hoagland in the Department of General Physiology, the head of which, W. J. Crozier, had worked with Jacques Loeb and was studying tropisms. I continued to prefer the reflex t o the tropism, but I accepted Loeb’s and Crozier’s dedication to the organism as a whole and the latter’s contempt for medical school “organ physiology.” Nevertheless, in the Department of Physiology at the Medical School I later worked with Hallowell Davis and with Alexander Forbes, who had been in England with Adrian and was using Sherrington’s torsion-wire myograph t o study the reflex control of movement. By the end of my first year a t Harvard I was analyzing the behavior of an “organism as a whole” under soundproofed conditions like those described by Pavlov. In one experiment I quiety released a rat into a small dark tunnel from which it could emerge into a well-lighted space, and with moving pen on a moving strip of paper I recorded its exploratory progress as well as its retreat into the tunnel when I made a slight noise. Some of m y rats had babies, and in their early squirmings I thought I saw some of the postural reflexes stereoscopically illustrated in Magnus’ Korperstellung,s and I began t o study them. I mounted a light platform o n tight wires and amplified its forward-and-backward movement with an arm writing on a smoked drum. I could put a small rat on the platform and record the tremor of its leg muscles or the sudden forward leap when I pulled it gently by the tail. I decided t o d o something of the sort with an adult rat. I built a very light runway about eight feet long, the lengthwise vibration of which I could also amplify and record o n a smoked drum, and I induced a rat to run along it by giving it food at the end. When it was halfway along, I would make a slight noise and record the way in which it came to a sudden stop by the effect o n the runway. I planned to watch changes as the rat adapted to the noise; possibly I could condition another stimulus t o elicit the same response. My records looked a little like those made by a torsion-wire myograph, but they reported the behavior of the organism as a whole. This was all pretty much in the tradition of reflex physiology, but quite by accident something happened that dramatically changed the direction of my research. In my apparatus the rat went down a back alley t o the other end of the apparatus before making its recorded run, and I noticed that it did not