The Lie Detector’s Big Lie

The fascinating American Experience documentary on the checkered history of the lie detector reveals that three separate men figure in the development of this flawed technology—ubiquitous in mid-century crime stories, television dramas, and still a staple of law enforcement and the intelligence community. Nevertheless, the physiological measures the polygraph records have not proved to demonstrate untruthfulness, the technology is easily defeated, it has failed in numerous significant cases, and it never met the objectivity test, either, as the behavior and skill of the examiner also influence the results.

Like so many disastrous inventions, the development of a machine that could tell truth from falsehood began with a laudable purpose. In the early 20th century, the brutal methods the police used to get information, known as the 3d degree, made a safe, “scientific,” and presumably objective way to obtain information seem like a good idea. Certain physiological measures (breathing and heart rate, blood pressure, etc.) had been put forward as markers of truth-telling, and medical student John Larson created a machine that would combine them. Each might be weak by itself, but together, they could create a powerful tool. Working for the Berkeley, California, Police Department, along with a high school student, Leonarde Keeler, Larson developed his prototype.

Larson’s first case revealed what would turn out to be his invention’s biggest flaw. Valuables were disappearing from a women’s dormitory on the Berkeley campus. Larson tested all of the residents, identified the culprit, and she left campus. Later she wrote Larson saying she was innocent, but had been abused as a child and feared his machine would betray her secret.

A second researcher, William Marston of American University, created a cruder machine, but convinced prosecutors to use it during a trial. Even today, some jurisdictions allow polygraph results to be used in the courtroom, despite the U.S. Supreme Court’s 1998 conclusion that they are “little better than could be obtained by the toss of a coin.”

Interestingly, both Larson and Marston ended up in Hollywood, where motion picture moguls wanted to measure how their films affected audience emotions. Neither lasted there. Today, Marston is best remembered as the creator of the comic book character Wonder Woman, who readily solved her creator’s shortcomings with her golden Lasso of Truth.

Later, Larson’s former assistant, Keeler, promoted his own machine, which he called the polygraph. He touted its infallibility to banks and retail outlets, who grabbed the opportunity to screen their employees on a regular basis. Eventually, hundreds of thousands of American workers were subjected to polygraphs, until most private employer screening was outlawed. Screening of national security and public safety personnel continues in some jurisdictions. (Note that polygraph use, certainly on such a widespread basis, is an almost wholly American phenomenon.)

When Congressman Richard Nixon challenged Alger Hiss to take a lie detector test, it wasn’t because Nixon believed in the technology, it was because he knew the public did. Hiss’s refusal sealed his fate and helped launch an era of using the polygraph as a tool for intimidation. With this development, Larson believed his invention had become a “Frankenstein’s monster.” This scene from The Wire, perfectly demonstrates how the unquestioning faith in “lie detectors” can be a tool for manipulation.

The truth is that, even though the polygraph is next-to useless in detecting lies, people harbor secrets. And they fear the technology will reveal them.

Art by George Pérez

1 thought on “The Lie Detector’s Big Lie

  1. A friend of mine was injured in the line of duty and had to leave on a disability pension. He then went to John Reid Lie Detector School and became a certified polygraph operator. He told me a lot about how the machines work, and also stressed the importance and skill of the operator. I once assisted on a polygraph test when a shopping mall had an polygraph operator come in toe administer tests to the night shift cleaning crew due to a rash of thefts from the stores. The crew was all composed of Hispanics, none of whom spoke English. They hooked them up to the machine and I asked them a series of questions in Spanish. Before one set of questions the operator told me to abruptly stop reading the series of questions and tell the guy being tested to multiply thirteen times fifteen, wait about ten seconds, and then tell him to disregard. I did so and afterward we looked at the readout. When I’d told him to do the math problem his physical reactions were noticeably affected. The operator told me that this guy would be a good candidate for an accurate polygraph reading.
    Incidentally, they all passed. It was later discovered that the person committing the thefts was one of the mall’s security staff.

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