be regarded as quite primitive and unscientific, such as immersion in water or placing a wafer on the tongue (see Kleinmuntz and Szucko, 1984). Despite the lack of scientific evidence supporting the validity of such techniques, they apparently are useful, as judged by their ability to elicit confessions of truths that are not forthcoming when other methods are used. Some or all of this usefulness is attributed to mystique—the systems of beliefs that surround and support the techniques.

The polygraph testing procedures currently used in the criminal justice system and in several government agencies in the United States and other countries fit this prototype ritual. A polygraph examiner subculture exists, complete with its own institutions (e.g., professional societies), norms, values, etc. Examiners are trained and certified expert by various training institutes, including some private ones and, importantly, by the U.S. Department of Defense Polygraph Institute. Members of the polygraph examiner culture have a particular jargon and shared lore that are generally unknown to others. They also maintain secrets because to reveal too much of their knowledge would enable targets of investigations to “beat” polygraph tests. The polygraph device or instrument is purported to have the power to discriminate lies from truths in the hands of a certified and experienced examiner.

The polygraph examination follows standardized, ritual-like procedures and usually occurs in a setting designed to evoke associations with science, medicine, or law enforcement, institutions whose certified practitioners are believed to have special powers to uncover truths. Claims that polygraph testing is a scientific method, together with the establishment of research programs to improve polygraph testing, are useful for building credibility in a society that confers credibility on scientific activities. Moreover, potential examinees are assumed to believe in the validity of polygraph testing, and its validity is supported by popular culture.

These similarities between current polygraph detection of deception procedures and the lie detection rituals of other and former cultures say nothing directly about the validity or invalidity of the polygraph testing for distinguishing truth from deception. They do, however, suggest that some of the value or utility of the polygraph for eliciting admissions and confessions undoubtedly comes from attributes other than the validity of the testing itself. Polygraph testing may work, in part, because it capitalizes on the mystique that is common to lie-detection rituals in many societies. Any investigation into the scientific validity of polygraph detection of deception must try to identify and distinguish between two kinds of scientific evidence: evidence bearing on the effects of the polygraph ritual and mystique and evidence bearing on the validity of polygraph testing and the polygraph device for detecting deception.

Any scientific investigation must also deal with some of the cognitive