Bekhterev's and Watson's research used a bell as a conditioned stimulus. the bell became identified with conditioning in the United States because of the notoriety Watson achieved as a result of championing conditioning as the major source of habit formation and learning.
At the 1991 meeting of the Pavlovian Society of North America in Baltimore, a poster with an enlarged photograph of Pavlov's desk stood next to the registration area. Prominent on the desk was a large bell with the presumable function of summoning a servant. I asked some participants at the meeting what they knew about Pavlov's experiments with bells, and none recalled any specific citation that documented Pavlov's actual use of a bell in an experiment. In summer 1993, in conjunction with a meeting in St. Petersburg, Russia, I had an opportunity to visit Pavlov's apartments (now a museum), and inquired further. Again, no one I asked had any information about whether Pavlov's experiments had ever included a bell.
Since then, I have examined Pavlov's book, "Conditioned reflexes" (Oxford University Press, 1927, in the translation by G. V. Anrep) and other writings of Pavlov, and I have not yet found any experiment in which a bell was used. Pavlov's auditory stimuli included metronomes, tones, hooters and buzzers. Perhaps the buzzers consisted of a bell and a vibrating clapper, but in the absence of more information that is only speculation. Perhaps Pavlov's original Russian text included bells but was not adequately translated. Or perhaps I have scanned the literature available to me carelessly, and missed one or more existing references to a bell as a stimulus.
It makes sense that Pavlov might have eschewed bells in favor of devices that presented auditory stimuli in a more consistent way. Unless a bell is rung by some automated system, it will produce more variable stimuli from trial to trial than such devices as metronomes or buzzers. My query, then, is this: Does anyone know of any literature documenting Pavlov's experimental use of a bell? It is probably safe to assume that Pavlov did not use his servants as experimental subjects. In the absence of relevant evidence, must we conclude that Pavlov's bell is a myth? If so, where did it originate?
Catania's recollection is convincing (and correct, I believe) that Pavlov (1927) did not use a bell in research. So whence the use of a bell as the conditioned stimulus (CS) in explanations that are found in textbooks and popular explanations? And, of course, in the famous question "Does the name Pavlov ring a bell?" Finally, did anyone actually use a bell in conditioning research? The answers follow.
2. V.M. Bekhterev (1928/1973), whose analysis of the nature and utility of conditioning differed markedly from Pavlov's, had a vigorous and productive laboratory during the first quarter of this century. He introduced the conditioning of motor responses as an alternative to the secretory, glandular responses that Pavlov studied. He did so partly because he was interested in education and mental health and envisioned conditioning as a powerful explanation of, and tool for, social and personal development and ameliorative aims which were very compatible with Watson's views; secretory behavior was too limited for such purposes. In addition, his ambitions for conditioning extended to its promise as an instrument for evaluating and comparing the characteristics and capacities of animals, from unicellular creatures to man again, in agreement with Watson's views as expressed in his addresses and texts. The School of Bekhterev was a formidable opponent to the School of Pavlov in the Soviet Union. Conditioning experiments by students and researchers in Bekhterev's labs regularly used sounds as CSs and the bell was often used. The estimable Gregory Razran (responsible for much of what was known in this country during the thirties and forties about Russian conditioning research through his reviews and translations) discusses a number of bell-using experiments in one of his reviews (Razran, 1934). That particular review is restricted to experiments with adult human subjects, while other reports took up conditioning in animals and children. Razran states, by the way, that the methods in Bekhterev's labs were generally superior to those in Pavlov's and Krasnogorskii's (1958) laboratories; this was an advantage that I believe came because it is easier to study motor-reflexes than salivary and other glandular reflexes.
3. Now, while Bekhterev and his students have clear priority in the use of bells in conditioning, I don't think they are responsible for the common association of the bell with conditioning. I believe that honor belongs to the founder of Behaviorism, John B. Watson, a very much unappreciated and underestimated psychologist, in my opinion.
4. In his presidential address to the American Psychological Association in 1915, Watson (1916) argued for the conditioned reflex as a universal instrument for understanding sensory and discriminative capacities across species, from lower forms to man. Although he discusses both Pawlowian and Bechterewian conditioning (sic: -- his orthography for both Russians), he clearly favors the motor-reflex method of Bekhterev. His talk, incidentally, provided the first account of Karl Lashley's (1929) efforts at conditioning the salivary response in humans, an effort that did not meet with success despite the elegant piece of apparatus that is depicted in the report. In any event, Razran notes that the research Watson was presenting to his colleagues was by the first non-Russian to establish a conditioned response to shock in humans, adding further to his laurels.
5. In Watson's motor-reflex research, in which Lashley participated, the procedure was uniform: bell as the CS, shock as the unconditioned stimulus (UCS), withdrawal as the unconditioned response (UCR), and withdrawal to the sound of the bell as the conditioned response (CR). In his address, Watson also describes a failed attempt to condition the galvanic-skin reflex to a bell with shock; later research by Hovland (1937), this writer (Littman 1949), and others using pure tones showed it could be readily done. Watson reports (and shows kymograph recordings for) differentiation between two different bell frequencies as well as a number of other conditioning phenomena. In addition to human subjects, Watson studied other animals: he shows the apparatus for a dog and kymograph recordings of its conditioned differentiation between two bells; he shows an owl in a harness but does not present any data for the creature. All in all, it is a fine bit of reporting by an excellent experimenter on a new way to study fundamental adaptive animal capacities and processes experimentally. It is true that the bell as a CS did not catch on among researchers, but the question here is a cultural one and not one of experimental rigor.
6. Why do I point to Watson as the source of the bell-image for conditioning? First of all, his presentation of conditioning to American psychologists was from the prestigious pulpit of a new Association president; that always attracts attention. As Watson himself pointed out, Yerkes and Morgulis (1909) had summarized much of the research in Pavlov's laboratories, but it is clear that it was with Watson that those summaries first caught fire in American psychology.
7. Second, Watson's exposition was thorough and clear; he was an excellent writer and a formidable advocate. And, he wasn't talking just about conditioning; he was talking about the key to bypassing all the problems of subjectivity in human cognitive and perceptual functioning that plagued psychology then (and still does, I might add). He spoke as a first rate scientist, from a perspective that viewed men and animals as functioning according to universal, biological principles.
8. In Watson's excellent text book of 1919, "Psychology from the Standpoint of a Behaviorist," conditioning played a critical role in demonstrating how habits could be developed and altered through conditioning. It was a tour de force, completing the promise (from his point of view) of his landmark 1913 paper, Psychology as the Behaviorist Views It, which preceded his election as APA president. By the time Watson's book appeared, and thanks to him, America's psychologists were quite familiar with conditioning. There were objections to his radical behavioristic ideas, but conditioning as a phenomenon worthy of study was thoroughly accepted. So research on conditioning proceeded apace in the academy.
9. On the other hand, Watson did little fundamental conditioning research after his first efforts owing to the entrance of the United States into WWI; he, Lashley, and other research and applied psychologists were recruited into the armed forces. On his return to academic psychology, Watson resumed the study of conditioning, focusing on the conditioning of emotional reactions in children; this was dramatic work but it hardly satisfied Watson's own rigorous criteria for good experimental research. The results, however, formed part of his 1928 book "Psychological Care of Infant and Child." He devoted his time increasingly to advocating conditioning's significance in child development, mental health, and society in general. His ideas were picked up by numerous psychologists who wrote texts on social psychology, mental health, and learning, by the linguist Bloomfield (1933), and others in sociology and political science, to name the most prominent loci of his influence. Conditioning replaced association as a mechanism by which people were thought to acquire language, personality characteristics, social skills, beliefs and values, and behavioral manifestations of abnormality; it involved procedures which could be specified and replicated in the laboratory and results that could be measured and, which hence, it was argued, promised to provide a coherent framework for psychology theory.
10. By the early nineteen-twenties, behaviorism and Watson were familiar in the popular mind. He was the subject of articles in newspapers, magazines, and intellectual and political journals. His controversial ideas even competed for attention with the equally controversial notions of psychoanalysis. Watson attracted particular attention because of his attack upon instinct theory and his argument that much of what seemed to be native in behavior was really learned, even prenatally. He took on the nature-nurture issue headfirst. There was no bad seed; parents (read mothers) were responsible for much of what their children were like when they grew up; the orderly appearance of many developmental patterns in children was to a great extent environmental. He used the great H.J. Muller's (1925) research with identical-twins to support his argument, and cited the equally great H.S. Jennings (1930, who had been his colleague at Johns Hopkins) for his judgment on the relative importance of environmental and genetic factors, a judgment that seems as judicious today as it was for Watson sixty years ago. Many of the views that are currently associated with B.F. Skinner (1938) were expressed by Watson -- and subjected to many of the same criticism and counterclaims, and defense and support.
11. Watson's views appealed to sociologists, anthropologists, and linguists who sought to explain the diversity that was the hallmark of their disciplines on scientific grounds. Watson was assailed and supported from the political, religious, medical, educational, philosophical, and scientific left, right, and center. Did he, in the end, have any influence? You bet! Many parents raised children according to his precepts (and many blamed him for the results, it might be mentioned). By the time he wrote the following in Behaviorism in 1924: "Give me a dozen healthy infants, well formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select -- doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations and race of his ancestors" (Watson, 1930), Watson was a name to be reckoned with in the home, in the school, and in the pediatrician's office. Grandma tales were out.
12. It is not surprising, then, that the idea of conditioning should be associated with a bell in common usage. Popularized illustrations and descriptive examples of how conditioning occurred were couched in terms of how Watson had done it: bell-shock; bell-shock; ... bell.
Bekhterev, V.M. (1928/1973) General Principles of Human Reflexology. [E. & W.Murphy, tr.]. New York: Arno Press.
Bloomfield, L. (1933) Language. New York: Holt.
Catania, A.C. (1994) Query: Did Pavlov's Research Ring a Bell? PSYCOLOQUY Newsletter, Tuesday June 7 1994.
Hovland, C.I. (1937) The generalization of conditioned responses. I. The sensory generalization of conditioned responses with varying frequencies of tone. Journal of General Psychology, 17, 125-148.
Jennings, H.S. (1930) The Biological Basis of Human Nature. New York: W.W.Norton
Krasnogorskii, N.I. (1958) Higher Nervous Activity in the Child. Leningrad: Medgiz.
Lashley, K.S. (1929) Brain Mechanisms and Intelligence. Chicago: University of Chicago Press.
Littman, R.A. (1949) The conditioned generalization of the GSR to tones. Journal of Experimental Psychology, 39, 868-882.
Muller, H.J. (1925) Mental traits and heredity. Journal of Heredity, 16, 433-448.
Pavlov, I.P. (1927) Conditioned Reflexes; An Investigation of the Physiological Activity of the Cerebral Cortex [G.V. Anrep, ed. tr.]. London: Oxford University Press.
Razran, G. H. (1934) Conditioned withdrawal responses with shock as the conditioning stimulus in adult human subjects. Psychological Bulletin, 21, 111-143.
Skinner, B. F. (1938) The Behavior of Organisms. An Experimental Analysis. New York: D. Appleton-Century.
Watson, J. B. (1913) Psychology as the behaviorist sees it. Psychological Review, 20, 158-177.
Watson, J. B. (1916) The place of the conditioned-reflex in psychology. Psychological Review, 23, 89-116.
Watson, J. B. (1919) Psychology from the Standpoint of a Behaviorist. Philadelphia: Lippincott.
Watson, J. B. (1928) Psychological Care of Infant and Child. New York: W.W.Norton.
Watson, J. B. (1930) (rev ed.) Behaviorism. New York: W.W.Norton.
Yerkes, R.M. and Morgulis, S. (1909) The method of Pavlov in animal psychology. Psychological Bulletin, 6, 257-273.