Study warns U.S.: Polygraphs can lie

By Michael Kilian
Washington Bureau

October 9, 2002

WASHINGTON -- The National Academy of Sciences declared Tuesday that polygraph examinations are dangerously unreliable and the federal government should cease depending on them to screen for security risks.

The academy's 18-month, federally-funded study found that the so-called lie detector not only incorrectly deems large numbers of people who are telling the truth to be liars, but may have allowed spies and others posing security risks into sensitive positions because they were able to pass polygraph tests.

This makes the devices themselves a security problem because so many agencies, such as the FBI and the Energy Department, rely on them, the report said.

"National security is too important to be left to such a blunt instrument," said Stephen Fienberg, a Carnegie-Mellon University computer science professor and chairman of the panel of academics who conducted the study.

Calling lie-detector technology badly outdated, the report urged the government to vigorously pursue research into prospective new lie-detection techniques, such as analysis of brain activity, voice stress levels and thermal imaging.

The blockbuster study, commissioned by the Department of Energy after the collapse of the government's case against Los Alamos espionage suspect Wen Ho Lee, and other national security problems, is expected to have enormous implications for the federal government at a time of intensified security worries.

Courts allow polygraph test results to be admitted as evidence only under very special circumstances, and their use on employees in the private sector was virtually outlawed by legislation signed by President Ronald Reagan in 1988.

Nevertheless, polygraphs are still widely used in criminal investigations and in a wholesale way by the federal government, according to study commission member Kathryn Laskey, associate professor of systems engineering at Virginia's George Mason University.

By law, personnel employed by the Energy Department's nuclear laboratories, intelligence agencies and in other sensitive areas are subject to polygraphs.

The Energy Department was guarded in its response to the report, but conceded it raises serious questions.

"The ... committee identified the fundamental conflict that we in the national security community must address: How to administer a program that is maximally effective in weeding out security risks while minimizing damage to the vast majority of loyal, patriotic employees?" said the department's acting national nuclear security director, Linton Brooks. "There is no easy answer, but it is a question that we will examine very seriously in the coming months."

Brooks called the polygraph "one of many tools we use to protect some of the nation's most sensitive secrets."

Northwestern University law professor Ronald Allen said the report will have an impact on government security screening but it should not have much impact on the legal system.

"Polygraphs are commonly used by police and prosecutors to determine the reliability of witnesses," Allen said.

"They are used by defense counsel for the same purpose. I don't think this report will change that. If anything, there's a slight trend toward admissibility [of polygraph tests as evidence] in some cases where all parties agree. The issue also has been raised of constitutionality in terms of an individual's right to introduce a polygraph test as evidence in his defense."

The first polygraph device was invented in the 1920s by Harvard University psychology professor William Moulton Marston, who also created the Wonder Woman comic book character.

Marston's invention measured fluctuations in systolic blood pressure, but the modern polygraph also tracks changes in respiration and skin moisture content from perspiring.

The device gained great currency in law enforcement and national security work in the 1950s and at one point, a million or more polygraph examinations were being administered in the U.S. every year, according to University of Minnesota professor emeritus David Lykken, an expert on the subject.

Lykken said that under some circumstances, a polygraph can be used to determine if someone has knowledge of a criminal act, but otherwise it is a poor screening device because it fails so many people telling the truth along with the actual liars.

"I think of all the excellent people we do not employ as scientists or federal agents simply because they failed to pass polygraphs," Lykken said.

Though it has fallen into disuse in the private sector, the federal government has continued to rely on it and expand its use. The polygraph had not been part of the FBI's agent selection process until 1994, when then-Director Louis Freeh made it a required part of the screening.

With the tremendous impetus given national and homeland security in the wake of the Sept. 11 attacks, use of polygraphs by the federal government was expected to dramatically expand.

Noting that about 5,000 nuclear lab employees were going to be subject to the tests in his state alone, Sen. Jeff Bingaman (D-N.M.) warned this would exacerbate serious morale problems at these sites.

The report flatly terms polygraph testing "unacceptable" as an employee screening device because of "too many loyal employees falsely judged deceptive and too many major security threats left undetected."

Tuesday's report noted that a variety of other factors having nothing to do with truth-telling can skew the results of a test, "such as anxiety about being tested."

"Also, people can learn ways to mimic some physiological responses of truthful test takers," the commission said.

The report blamed popular culture and the mass media for the devices' image as "magical mind-reading machines."

Copyright © 2002, Chicago Tribune

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