William J. Broad reports for the New York Times. Excerpt:
In a report to the government, a panel of leading scientists said yesterday that polygraph testing was too flawed to use for security screening. The panel said lie-detector tests did a poor job of identifying spies or other national-security risks and were likely to produce accusations of innocent people.
The 245-page report, by experts convened by the National Research Council, an arm of the National Academy of Sciences, said that the scientific basis for polygraph testing was weak and that much of the research supporting its use lacked scientific rigor.
Recently, worries over possible atomic espionage prompted widespread use of polygraph screening at the nation’s nuclear weapons laboratories, which are run by the Energy Department. That department requested the 19-month study and financed it.
The report is not the first to question the reliability of lie-detector testing, which is known to have limitations that make its admissibility in court, for example, sharply limited. But it is the first by the academy, and private security experts said its findings could erode support for polygraph testing inside the federal government. Defense and intelligence agencies use polygraph testing tens of thousands of times a year as part of the screening of prospective and current employees for espionage.
“National security is too important to be left to such a blunt instrument,” said Stephen E. Fienberg, a professor of statistics and computer science at Carnegie Mellon University and the panel’s leader. “The polygraph’s serious limitations in employee security screening underscore the need to look more broadly for effective, alternative methods.”
The report said lie tests, which measure pulse and breathing rates, sweating and blood pressure, had some usefulness in investigating particular crimes but were far from totally reliable. But in routine security screening, the panel said, they often flag innocent people as lying, while missing actual security risks.
“No spy has ever been caught using the polygraph,” Kathryn B. Laskey, a professor of systems engineering at George Mason University and a panel member, told reporters.
The council is the research arm of the National Academy of Sciences, an organization of eminent scientists chartered by Congress to advise the government on scientific matters. The report is the academy’s first formal assessment of polygraph testing. The panel performed its evaluation by reviewing previous research on lie detector tests and by visiting centers where the tests are performed and developed.
White House officials said the academy report would be carefully studied.
“It’s important to note,” said Gordon D. Johndroe, spokesman for the White House Office of Homeland Security, “that polygraph examinations are one small part of a very comprehensive background investigation” for people in the government’s most sensitive programs.
Steven Aftergood, a security expert at the Federation of American Scientists, a private group in Washington, said the report could be decisive in the long-standing debate over the polygraph’s reliability. “People will still want to use it, but they will no longer be able to say experts disagree” on its usefulness, he said. “They don’t.”