Lies, Damned Lies and Polygraph Tests
Lehrer, Eli, Insight on the News
The original technology has been married to a computer and, in the hands of professionals, it is becoming hard to fool the machine. Courts and cops are taking notice.
When Maj. Gen. David R. Hale denied Donnamaria Carpino's accusations that he had forced her into a sexual relationship last year, Carpino had a quick retort: "I took a polygraph on that and passed," she told the Washington Times. "The [inspector-general's] report says that it's unsubstantiated, not that it's untrue."
Although Carpino's ability to pass a polygraph test probably never will make it into any hearing, it may prove effective in the court of public opinion. "I can be quite sure that Donna believes she is telling the truth," says Danny Bragg, the Virginia polygraph examiner who tested her.
Polygraph use significantly has declined since the 1988 Employee Polygraph Protection Act essentially banned private-sector employers from using "lie detectors" but it has begun to inch up in recent years.
Although its membership of around 2,000 stands at roughly half of its 1988 level, the American Polygraph Association, or APA, reports that it hasn't had a monthly membership decline in more than four years.
According to APA, 36 states allow the use of polygraph evidence in court, although all but New Mexico require that both sides agree to it. Federal courts leave polygraph-evidence admission up to judges. Polygraph professionals say that such limitations are dated. "Comparing the technology when these decisions were made to the technology today is like comparing the space shuttle with the Wright Brothers' original," Bragg tells Insight.
Skeptics and polygraph professionals agree that the fundamental technology, which measures breathing, pulse, blood pressure and galvanic skin response (sweating) has remained unchanged since William Marston (who also created the Wonder Woman comic) refined it in the 1930s. APA President Richard Keifer says that computers have simplified the work but agrees that the measurements have not changed.
"They've added computers, but that just marries the myth of the lie detector to the mystique of the computer," David Lykken, a professor of psychology at the University of Minnesota, Twin Cities, and the author of the recently revised 1981 book, A Tremor in the Blood: The Uses and Misuses of the Lie Detector, tells Insight. "We have not developed an involuntary response that we show when we are lying," he says.
Lykken also contends that polygraphs are easy to fool, a contention that has made Doug Williams' reputation. …