Even J. Edgar Hoover knewâ€¨that the polygraph wasn’t any good for detecting deception. He dropped theâ€¨test.
Theâ€¨polygraph was invented in 1915 by a Harvard man called William Moulton Marston,â€¨ who claimed that his clunky little gizmo could detect lies by measuring bloodâ€¨pressure. Marston’s main claim to fame derives not from his machine, butâ€¨from a doodle he came up with: the cartoon character Wonder Woman.
Inâ€¨the past 85 years, the polygraph hasn’t changed much from the Marston prototype.â€¨”The secret of the polygraph is that their machine is no more capable ofâ€¨telling the truth than were the priests of ancient Rome standing knee-deep inâ€¨chicken parts,” says Alan Zelicoff, a physician and senior scientist at theâ€¨Center for National Security and Arms Control at the Sandia Labs in Albuquerque,â€¨NM. Zelicoff gave us this view in an article featured in the The Skeptical Inquirer.
Heâ€¨writes that the polygraph administrator is a kind of confidence artist or modernâ€¨day mesmerist who tries to seduce (or scare) his subjects into believing in theâ€¨power of the machine to catch them in the most minute inconsistency.
“Theâ€¨subject, nervously strapped in a chair, is often convinced by the aura surroundingâ€¨this cheap parlor trick, and is then putty in the hands of the polygrapher, whoâ€¨then launches into an intrusive, illegal and wide-ranging inquisition,” Zelicoffâ€¨writes. “The subject is told from time to time that the machine is indicatingâ€¨‘deception.’ It isn’t, of course. And he is continuously urgedâ€¨to clarify his answers, by providing more and more personal information.”â€¨At an arbitrary point, the polygrapher calls off the testing, consults the spoolsâ€¨of graph paper and makes an entirely subjective rendering on whether the subjectâ€¨has given a “deceptive response.”
“Everyâ€¨first-year medical student knows that the four parameters measured during a polygraph—bloodâ€¨pressure, pulse, sweat production, and breathing rate—are affected by anâ€¨uncountable myriad of emotions: joy, hate, elation, sadness, anxiety, depression,â€¨and so forth,” says Zelicoff. “But there is not one chapter—notâ€¨one—in any medical text that associates these quantities in any way withâ€¨an individual’s intent to deceive. More importantly, dozens of studies overâ€¨the past 20 years in psychology departments and medical schools all over the worldâ€¨have shown that the polygraph cannot distinguish between truth-telling and lying.”
Connoisseursâ€¨of the Wen Ho Lee affair will remember that at one point the FBI falsely toldâ€¨the Taiwanese nuclear physicist (accused of spying for the Chinese at Los Alamos)â€¨that polygraph tests showed he was lying. Cops play these sorts of tricks allâ€¨the time, faking forensic reports and then shoving them under the nose of theirâ€¨suspect, shouting that he’s a proven liar and that he’d best sign aâ€¨confession right away.
Theâ€¨most comprehensive review of the polygraph was conducted in 1983 by the Officeâ€¨of Technology Assessment, a research branch of congress. The OTA concluded, “Thereâ€¨is no known physiological response that is unique to deception.” The reportâ€¨did note that the CIA and its companions “believe that the polygraph is aâ€¨useful screening tool.” However, OTA concluded that the available researchâ€¨does not establish the scientific validity of the polygraph for this purpose.â€¨The best that OTA could say about the polygraph was that it might have some limitedâ€¨validity in “specific criminal incidents.” But the report went on toâ€¨observe that in such cases, “the polygraph test detects deception betterâ€¨than chance, but with error rates that could be significant.” As for theâ€¨supposedly revealing physiological responses, the congressional study reportedâ€¨that they could be masked “by physical movement, drugs or other techniquesâ€¨to avoid detection as deceptive.”
Thereâ€¨are numerous ghastly stories of federal employees who were abused by the machineâ€¨and its operators. Take the case of 19-year Navy veteran Daniel M. King, who wasâ€¨suspected of selling classified information. King was locked up in military prisonâ€¨in solitary confinement for 500 days and subjected to repeated polygraphs. Someâ€¨of them lasted for as long as 19 hours. A military judge dismissed all the chargesâ€¨against him.
Aâ€¨few years ago FBI agent Mark Mallah was given a routine polygraph. The polygrapher,â€¨ who had only 80 hours of experience with the machine, concluded that Mallah hadâ€¨lied. (Zelicoff notes that even barbers must have 1000 hours of training beforeâ€¨getting a license to cut hair.) His life soon transformed into a Kafka story.â€¨ He was stripped of his badge, subjected to midnight searches of his house, hisâ€¨diary and appointment book seized and scrutinized, his neighbors, friends andâ€¨relatives interrogated, his every move outside monitored by helicopters. In theâ€¨end, Mallah’s life was pretty much destroyed, but nothing was ever provedâ€¨against him. The FBI finally apologized and Congress outlawed the use of the polygraphâ€¨for civilian employees in 1988.
It’sâ€¨worth noting that the Walker brothers and Aldrich Ames both beat the polygraphâ€¨with no sweat. Kim Philby settled himself with a dollop of Valium before breezingâ€¨through his polygraph exams.
Oneâ€¨investigator for a defense lawyer in California told us that, while the polygraphâ€¨isn’t admissible in most courts, it’s used all the time by prosecutors,â€¨mostly to seal plea bargains. “It’s a perilous option, because the utilityâ€¨of the polygraph is almost totally up to the operator,” she said. “There are good polygraphers,â€¨but many who work for the district attorneys have only minimal training.”
Theâ€¨investigator described a recent case where a defense witness in a homicide case,â€¨ who had passed a polygraph given by a former FBI polygrapher with 20 years ofâ€¨experience, was sent to the DA for another test given by their examiner, a relativeâ€¨novice with the device. Defense lawyers can’t be in the room while the testâ€¨is given, even when their clients are being examined. The prosecutors videotapeâ€¨the session, and while the results of the polygraph can’t be used at trial,â€¨the videotape can become evidence. In this case, the defense lawyer waited inâ€¨the hall until the witness emerged from the room “with his face red as aâ€¨beet.” The lawyer heard the DA’s investigator threaten the witness:â€¨”You little slimebag, I know you’re lying. We’re going to revokeâ€¨your parole.” The DA’s examiner had interpreted the readings from oneâ€¨of his answers as being “deceptive.”
Jeffrey St. Clair is the author of Been Brown So Long It Looked Like Green to Me: the Politics of Nature, Grand Theft Pentagon and Born Under a Bad Sky. His latest book is Hopeless: Barack Obama and the Politics of Illusion. He can be reached at: email@example.com.
Alexander Cockburn’s Guillotined! and A Colossal Wreck are available from CounterPunch.
This essay is adapted from an article in the July 2001 edition of CounterPunch.