Polygraph examiners and the decision makers who use their reports do not always make such distinctions. The belief among many agency officials that the important questions about polygraph testing validity have already been favorably resolved makes it difficult to conduct scientific analysis of the components of polygraph testing, including the polygraph instrument itself, in those agencies. It also creates resistance to scientific evidence critical of the test’s validity among practitioners whose personal experience has convinced them of the polygraph’s utility. Finally, placing polygraphic detection of deception within the anthropological and historical context of lie detection rituals strongly suggests that the mystique will outlive current lie detection techniques, including the polygraph test. We surmise that if the mystique of lie detection no longer attaches to the polygraph, a new technique or instrument will take its place and assume its mystique. Indeed, some people argue that the mystique has already been dispelled, as exemplified by the controversy over polygraph security screening that led to the request for this study. It is therefore not surprising that in the current context of heightened concern about espionage and terrorism, there is a lot of publicity about new devices and techniques for the psychophysiological detection of deception. This interest reflects both the need for security and at least latent doubts about the validity of polygraph testing procedures. As discussed in this report, the scientific criteria that should be used to evaluate new devices and procedures are the same as those that apply to the polygraph.

SCIENTIFIC ISSUES

Detecting Deception and Eliciting Truth

For a criminal investigator or a counterintelligence officer, detecting deception and eliciting truth are opposite sides of the same coin. It does not matter whether deception is detected in an interviewee’s physiological responses or whether truth is elicited in the form of an admission or revealed by a combination of physiological responses and further interrogation and investigation. Such distinctions are not made in official reports on polygraph screening programs. What matters most to investigators and is reported to Congress are the number of examinees who were ultimately “cleared,” the number subjected to adverse personnel actions, and the security violations revealed.

From a scientific standpoint, however, detecting deception and revealing truth are two distinct purposes of polygraph examinations or any other technique for the psychophysiological detection of deception. The polygraph test is advocated as an accurate psychophysiological indicator of deception. The polygraph examination, which includes the test and the interrogation surrounding it, is a tool for revealing truth. To



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