In 1959, University of Minnesota psychology professor David Lykken reported an experimental study of a new type of lie detector test that he termed the “Guilty Knowledge Test” (GKT). As indicated in the foregoing quote from his 1981 book, Lykken was unfamiliar with established methods of lie detection used by police and other field examiners at the time of this study. As a result, he relied upon basic principles of experimental psychology to devise a test that focused on probing for specific relevant knowledge of the incident under investigation rather than on detection of lying per se.

A cornerstone of Lykken's technique was the fundamental concept of experimental control: to ensure that the observed (“dependent”) effect is attributable to the experimental (“independent”) manipulation, one must establish a comparison condition that mirrors the experimental condition in all respects aside from the manipulation of interest. With this principle in mind, the GKT was composed of items in multiple-choice format, with alternative choices for each item (one of them crime-relevant, the others extraneous) formulated to appear equally plausible to an innocent examinee.