Mueller's Pascalian Wager
John Roberts' Ironic Argument

A History Of The "Lie Detector"

I doubt I will ever forget the polygraph exam that I failed back in the early 1980s. I sat huddled with an examiner at the headquarters of the CIA. I was peppered with questions about drug use and whether I was gay. I answered truthfully, but not to the satisfaction of my examiner. Result? I never became a spy.

That was no loss to the nation's security, and it probably kept me from a career path that would have landed me in prison for insubordination or worse. But I've never trusted the machines since. Ken Adler's The Lie Detectors: The History of an American Obsession (Free Press: New York, 2007), helped put that mistrust in perspective.

It is a truism to say that science has transformed our understanding of the world and of ourselves. In the early twentieth century, it was tempting to say we were simply the sum of our physical reactions to stimuli. Thus, a body could be read, and concepts, such as truth, could be given a corporeal meaning. And if the natural sciences could work such wonders, then couldn't the social sciences reorganize such things as law enforcement itself? Technique was the rage.

August Vollmer, the former chief of the Berkeley, California police department, harnessed the energies of John Larson and Leonarde Keeler. Larson, a Ph.D. cop with an inquiring mind put together the first working "lie detector." Soon Keeler patented a polygraph and was everywhere at once trying to ferret out the truth. In time, Larson soured on the reliability of polygraphs, but Keeler pressed on.

Today, polygraphs are almost never admissible in a court of law. Apparently, only New Mexico permits them with some regularity. Even though the machines arguably satisfy the Daubert test for the admission of expert testimony, courts are reluctant to permit their admission, fearing that jurors will be seduced by the allure of men and women in lab coats spouting truths that have been detected in blood pressure, respiration rates and sweat.

But the device is still common in law enforcement. Not long ago, one of my clients was required to pass a polygraph to obtain the benefit of a plea that would permit him to remain in the United States to support his famiy. He passed, after several tense sessions. I felt helpless as his lawyer watching his frustration with the examiner. What were we measuring?

Polygraphs are not beyond misuse in law enforcement hands, which comes as no surprise. Consider the case of Wen Ho Lee, accused of pilfering nuclear secrets. Examiners badgered him and then leaked to the press that he had failed the exam when, in fact, the exam was merely inconclusive. Even al Qaeda offers training on how to beat the exam. According to Adler, the device is merely a tool, a psychologically kind form of the third degree.

Efforts to replace ordinary jurors with infallible means of determining when a witness is truthful continue. Neuroscientists now chart brain waives trying to locate the spot at which our brains register deception. But neuroscience is no better than physiology in dissecting our sense of self.

Adler's book is fascinating, but it did not inspire me with the dread of the polygraph that Adler shares. A polygraph is a tool. A flawed device with strengths and limits, much like other tools. It has its uses.

For all its strengths, this book is slightly out of focus. I care less about petty rivalries between Larson and Keeler, and whether another polygraph pioneer lived happily in a menage a trois, than I do about what science can contribute to the truth-finding process. To say, as Adler does in his epilogue, that "to deceive is human," is merely to repeat another truism.