Julian Coman reports for The Telegraph of London. Excerpt:
One of America’s most famous detection devices may be consigned to the scrapheap after being used in thousands of trials and making countless appearances in Hollywood films.
The lie-detector, or polygraph test, is routinely used by United States police forces, the FBI, the Pentagon and other government departments in order to investigate crimes, screen employees and root out spies.
O J Simpson failed one after being accused of murdering his wife. In the recent hit film, Meet the Parents, Robert De Niro played an ex-CIA man who even subjects a prospective son-in-law to a polygraph test to discover his true intentions.
A government-sponsored study by the American Academy of Sciences concludes, however, that the suspicious father was wasting his time.
Two years of research has led the academy to report that the lie-detector, which measures abnormal blood pressure, breathing and skin response during interrogation, is so inaccurate and vague that it actually constitutes a “danger to national security”.
Drew Richardson, a former FBI special agent and consultant to the report, said: “Panel members very clearly and emphatically found that no spy has ever been caught as a result of a polygraph.
“None would ever be expected to be revealed and large numbers of the tens of thousands of people subjected yearly to this sort of testing are probably being falsely accused about their backgrounds and activities.”
Dr Stephen Fienberg, a computer scientist who headed the academy panel that produced the report, said: “The deep flaws with the lie-detector are to do with the thresholds set by interrogators.”
The panel found that to catch eight out of 10 spies, an estimated 1,600 innocent interviewees would also be placed under suspicion, rendering the results meaningless.
Eliminating the so-called “false positives” would mean that almost no genuine targets would ever be caught.
“National security is too important to be left to such a blunt instrument,” said Dr Fienberg.
“There is a mystique about the lie-detector that very much needs to be addressed. It has led to an overconfidence about the status of its results in the popular mind.