"Willard Fordyce, working with physician John Bonica, reconceptualized subjective ( and therefore unreachable) "pain" into observable and measurable "pain behaviors," and showed that these respond to reinforcement contingencies just like all other behaviors. Fordyce and Bonica's program at the University of Washington was the first modern, interdisciplinary, and effective pain clinic."
January 1, 1970
https://en.wikiquote.org/wiki/John_Bonica