During the 1960s, my university accepted a secret research contract from the Air Force to study the effectiveness of countermeasures against lie detection. My job in this project was to train the experimental subjects. They practiced controlling their responses to my questions while observing their own reactions on the polygraph—the technique now known as "biofeedback." When I thought they were prepared, I would send them on to the chief of our university police department, a polygraph examiner of long experience, who would administer a formal lie test. This work had just gotten well under way when a new university president cancelled all secret research contracts, including ours. (I never understood why the Air Force insisted o the "secret" classification, since the only thing about our project that could really be kept secret was the source of the funding.) But we had gone far enough by then to convince me that some people could learn to attenuate their relevant responses and beat the lie detector in that fashion—but that it is very difficult for most people and probably impossible for many.