Edwin B. Twitmyer

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E. B. Twitmyer (1873-1943) was Professor of Psychology and Director of the Psychological Laboratory and Clinic at the University of Pennsylvania. He is a little known figure in the history of psychology, but he independently discovered Classical Conditioning at approximately the same time as the famous Russian physiologist, Ivan Pavlov, who is normally given credit for this achievement.

Twitmyer initially studied the patellar tendon reflex, and devised an apparatus that delivered a light tap below the knees of his research subjects in order to elicit this reflex. Twitmyer warned his subjects that the the tap was about to be delivered with a bell. During the course of his research, the sound of the bell was accidentally presented to one of his subjects without the tap below the knee. In a case of serendipity quite like Pavlov's, Twitmyer realized that the auditory stimulus was sufficient to produce the now conditioned reflexive response.

Twitmyer replicated the experiment with six more subjects and found that all of them learned to associate the bell with the hammer, and would produce the response to the sound of the bell alone. This typically took several dozen trials and the conditioned response was not only unintentional, but several of his subjects found themselves unable to prevent the response even when they attempted to do so. This finding is the first experimental demonstration of classical conditioning in a human being.

Twitmyer published this research in his doctoral dissertation in 1902, one year before Pavlov announced the results of his research with dogs at the 1903 International Medical Congress in Madrid. He also presented his work at a meeting of the American Psychological Association in 1904, presided over by William James. His paper, Knee jerks without simulation of the patellar tendon, was given late in the session, well-past the scheduled lunch break, and drew little response from the crowd. ^[1]

No one at the time realized the significance of the discovery. Perhaps it seemed more physiological than psychological, or maybe the time was not right. In any event, Twitmyer faded into obscurity, only a few years before John B. Watson would introduce classical conditioning to America with a resounding effect.

[edit] Bibliography

Coon, D. J. (1982). Eponymy, obscurity, Twitmyer, and Pavlov. Journal of the History of Behavioral Science, 18, 255-262.
↑ Hothersall, D. (2004). History of Psychology. McGraw-Hill.
Irwin, F. W. (1943). Edwin Burket Twitmyer: 1873-1943. The American Journal of Psychology, 56, 451-453.
Twitmyer, E. B. (1905). Knee jerks without simulation of the patellar tendon. Psychological Bulletin, 2, 43.
Windholz, G. (1986). A comparative analysis of the conditional reflex discoveries of Pavlov and Twitmyer, and the birth of a paradigm. Pavlovian Journal of Biological Science, 21, 141-147.