When B.F. Skinner Discovered Shaping

This paper reveals a fascinating piece of scientific detective work by Gail Peterson, Ph.D., a professor of behavior analysis at the University of Minnesota. During World War II, Skinner and some of his graduate students conducted classified research on pigeon-controlled guidance systems, at a secret laboratory in Minneapolis. One day, while waiting for government approval on their next steps, they decided to pass the time by trying to train a pigeon to “bowl.”

Because it was not a formal research effort, Skinner just detached the feeder switch and operated it himself, “clicking” it when the pigeon looked at the ball, and then when the bird touched it, and then when the bird pecked it harder. Before that, behavior had been reinforced in Skinner’s laboratory animals and pigeons by automated feeders, not by a flexible human-operated feeder. Very quickly the pigeon was whacking the ball all over the compartment. The team recognized that something new had happened, a process which Skinner immediately dubbed “shaping.” Skinner at once recognized the value and the dyadic, interactive nature of the shaping process. Peterson concludes that it changed the direction of not only Skinner’s work but the science; and he mentions that the then astonishing event certainly launched a life’s work for one of those graduate students, Keller Breland.

Gail Peterson attended ClickerExpo as an Honored Guest, and pointed out to me the building this took place in. I first saw this wonderful paper in manuscript. It appeared in the Clicker Journal, and was then published, with illustrations, in the scientific journal, Behavior Analysis, from which this reprint is taken.

Please note this article was originally published on 01/01/2004 and last reviewed on 06/11/2025. We regularly review our content to ensure that the principles and techniques remain valuable and relevant. However, best practices continue to evolve. If you notice anything that may need updating, please feel free to contact us at editor@clickertraining.com.