graph testing, this conclusion applies to any population of examinees that has the very low base rates of major security violations, such as espionage, that almost certainly exist among the employees subjected to polygraph screening in the DOE laboratories. Because the innocent will be indistinguishable from the guilty by polygraph alone, investigative resources would have to be expended to investigate hundreds of cases in order to find whether there is indeed one guilty individual (or more) in a pool of many individuals who “fail” a polygraph test. The alternative is to terminate or interrupt the careers of hundreds of innocent and productive individuals in an attempt to prevent the activity of one potential spy or saboteur.

Failure to Detect with “Friendly” Thresholds Polygraph screening programs can reduce the costs associated with false positive findings by adopting techniques that reduce the likelihood that innocent examinees will “fail” a polygraph test. However, polygraph screening programs that produce very small proportions of positive results, such as those reported by DOE, the U.S. Department of Defense (DoD), and the Federal Bureau of Investigation (FBI), can do so only at the cost of failing to accurately identify the majority of deceptive examinees. This conclusion applies to any population with extremely low base rates of the target transgressions, and it holds true even if none of the deceptive examinees uses countermeasures.

Use in DOE Employee Security Screening Polygraph testing yields an unacceptable choice for DOE employee security screening between too many loyal employees falsely judged deceptive and too many major security threats left undetected. Its accuracy in distinguishing actual or potential security violators from innocent test takers is insufficient to justify reliance on its use in employee security screening in federal agencies. If polygraph screening is considered because of its potential utility for such purposes as deterrence and elicitation of admissions, it should be remembered that a policy with a relatively friendly threshold that might enhance these forms of utility cannot be counted on to detect more than a small proportion of major security violators.

Danger of Overconfidence Overconfidence in the polygraph—a belief in its accuracy not justified by the evidence—presents a danger to national security objectives. A false faith in the accuracy of polygraph testing among potential examinees may enhance its utility for deterrence and eliciting admissions. However, we are more concerned with the danger that can arise from overconfidence in polygraph accuracy among officials in security and counterintelligence organizations, who are themselves potential examinees. Such overconfidence, when it affects counterintelligence and



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