Can I beat a lie detector?

Humiliating myself for fun and profit.
Jan. 27 2005 6:25 PM

Can I Beat a Lie Detector?

I always tell the truth. But not today.

Illustration by Nina Frenkel

I am sitting on a pad that sends an electronic signal to a computer every time I move my body. Circling my chest and abdomen are two rubber tubes, the pneumographs, which monitor my breathing. Tiny metal electrodermal plates secured to the index and ring fingers of my right hand with Velcro strips are measuring how much I sweat. A blood-pressure cuff is inflated tight around my left arm. Interrogating me about my moral failings is Darryl DeBow, owner of the Virginia School of Polygraph. I am lying my head off to him, just like—depending on your politics—Bill Clinton or George W. Bush.

Emily Yoffe Emily Yoffe

Emily Yoffe is a regular Slate contributor. She writes the Dear Prudence column. 

I'm also flexing my anus as if I'm in a proctological triathlon—but more on that later.

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For this "Human Guinea Pig," the column in which I do stuff you'd rather not do yourself, my plan is to see if I can beat a lie detector test. Although I'm a person of impeccable ethics, the whole idea of taking a polygraph exam, let alone trying to outfox it, has me in a state of fretfulness resembling Lady Macbeth in the fifth act. (OK, maybe I more resemble Ben Stiller facing Robert De Niro in the polygraph scene in Meet the Parents.)

To prepare myself, I read online advice on how to fool the machine. I consulted the comprehensive Antipolygraph.org, co-founded by George W. Maschke, who became an activist when he was turned down for a job with the FBI because of what he says was a false finding of deception during his required polygraph. I also spent $19.99 for a seven-page manual from Polygraph-test.net, which promised, "With the techniques in this manual you will be able to fool the machine so that you can successfully pass your exam no matter what!"

First, I learned, I had to understand the types of questions I was being asked. Polygraphers generally ask both "control" and "relevant" questions. Control questions are an unnerving tour of your past transgressions. An example might be (not that I was asked this), "Have you ever noticed that the dog has taken a dump in the house but pretended you didn't so your spouse will clean it up?" The relevant questions are pointedly specific about what the exam is really trying to uncover. For instance (and not that I was asked this, either), "Do you know where Jimmy Hoffa is buried?"

The purpose of the control questions is not actually to find out whether you stick your spouse with the dirty work, but how your body responds to anxiety-provoking questions. It's the relevant questions the examination is really designed to answer. So, if you didn't have anything to do with Jimmy Hoffa's disappearance, your confident denials about his whereabouts will elicit a milder response than to the control questions. But if you were involved, and said you weren't, then your guilty knowledge should create Mount Everests on the graph.

My online research said that beating the machine was easy. During the control questions I simply had to send the needles into a frenzy. Then, when I lied on the relevant questions, the needles (actually the simulated needles—polygraphs have gone digital and the examiner is looking at a computer screen) would remain calm. All that was required to cause the frenzy was the activation of a powerful weapon already in my possession: my sphincter. As the $19.99 manual explained, "[S]lowly flex your anus." Antipolygraph.org somewhat more romantically described the action as an "anal pucker."

Both warned not to overdo it, or get my buttocks muscles involved, lest the gauge I was sitting on reveal my squeezes. If the examiner picked up that I was using this or any other countermeasure, the session would be ended and I would be branded as deceptive. To perfect my technique I needed to practice daily, occasionally sitting on my hands to make sure my buttocks remained inert. Though I did my exercises, I doubted that double agent Aldrich Ames beat all those CIA lie detector tests because he had a sphincter of steel.

Lie detectors have been controversial since they were first used during the early 20th century. Even the matter of who should be given recognition for the creation of the modern lie detector is a matter of dispute. According to the National Research Council, credit—or blame—belongs to psychologist William Marston, who made another contribution to popular culture that has also sent hearts racing for decades. He is the creator of Wonder Woman.

Marston was an expert witness in a 1923 murder case in which he argued that polygraphs should be admissible. An appellate court was not persuaded as to their scientific reliability, and ever since polygraphs largely have been excluded from trials. Despite this, the federal government and local law-enforcement agencies are ever-larger consumers of polygraph exams. They are used not only to try to make people confess to crimes, but also as an employee-screening tool.

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