The lie detector has an interesting and colorful history. It elbowed its way into the news recently when the FBI began subjecting agents to lie detector tests as a way of gauging their loyalty to the agency’s esteemed director, Kash Patel.
How do you reach inside a person’s mind and determine what he’s really thinking? In the early twentieth century, researchers thought they had an answer — by tracking physical changes in a person’s body you could root out a fib.
William Marston, an American psychologist, came up with the Marston Deception Test around 1917. The machinery he used was dubbed by the press a “lie detector.” Marston declared that his method was a foolproof means of “distinguishing truth-telling from deception.”
The idea was that while a suspect could control what he said in answer to a question, he had no command of his physical responses. A lie would elicit a spike in blood pressure, speed his breathing, and set his heart aflutter. Marston deemed his machine “practically infallible.”
During the coming decade, the inventor beat a drum to popularize the lie detector. He toured with a stage act involving show girls that scientifically demonstrated brunettes’ more vigorous reaction to amatory stimuli compared to blondes. He helped promote Gillette products by declaring that the lie detector “reveals startling facts about razor blades!”
Although the U.S. Supreme Court ruled in 1923 that lie detector results were inadmissible as evidence in Federal courts, states were allowed to decide for themselves. Before he faded from the stage of history, Marston staked out one more claim to fame: he invented the comic book character, Wonder Woman. He dreamed up a tool for the patriotically garbed superheroine — a “Lasso of Truth” whose embrace forced victims to tell the truth.
A California police patrolman named John Larson next took up the lie detector banner, refining the equipment so that it recorded everything in squiggly lines on a moving sheet of paper. He called this an “ink polygraph,” which had a more scientific ring.
What the polygraph lacked was a grounding in actual science. Its validity rested on a shaky stack of assumptions about the connection between the mind and the body. But none of those assumptions could be nailed down through rigorous testing. Emotion is always a slippery item. Nervousness, fear, guilty knowledge, or physical pain might all produce the same response.
Larson went on to become a forensic psychiatrist. After working with the polygraph for several years, he lost faith in the technique. He judged it “nothing more than a psychological third degree.”
Police agencies across the country, seeking an alternative to the real “third degree,” embraced the lie detector during the 1930s. The equipment was streamlined into a portable machine. A polygraph school began offering a six-week course to certify operators.
Research within the polygraph industry consistently judged the equipment to be accurate from 90 to 95 percent of the time. But how to determine accuracy was a vexing problem. In a laboratory, a college student might be instructed to act out a theft and then lie about it. But would his reaction match that of a man who had actually committed murder?
In part, the machine’s name and reputation were its greatest asset. If the subject figured that his falsehood would be infallibly detected, he might blurt out the truth. If he was told he had “failed” the test, he might be prompted to confess.
Some said that a lie detector was simply a prop used for interrogation. It was actually the operator’s skill at observing the suspect’s behavior during questioning, his tone of voice or nervous tics, that uncovered the lies.
It was also known that rather simple methods could be used to “beat” a test. The subject might curl his toes, bite his tongue, or think of emotion-laden imagery as a way to throw off results.
Over the years, the lie detector has been the subject of frequent criticism as a pseudoscientific gadget. In 1963 a Congressional study declared, “There is no ‘lie detector,’ neither mechanical nor human.” Ten years later another committee advised the government to abandon polygraph testing altogether.
Yet even today, many states allow lie detector evidence in court under certain circumstances, such as when the defense and prosecution both agree to it. In an Ohio murder case, a suspect was given the option of taking a test. Knowing he was innocent, he agreed. He failed the exam and went to jail. Years later, he was cleared when the actual murderer was apprehended.
In the 1960s, lie detectors moved into a fertile new realm: employee screening. But privacy concerns led to a 1988 federal law that made it illegal for employers to require a lie detector test for job applicants or workers. The law, however, did not apply to the government itself.
In these days of rampant conspiracy theories, when truth is so often thrown into question, determining who is lying and who is being honest is more important than ever. But whether a machine will ever serve as a reliable Lasso of Truth remains to be seen.
Thanks, Jack, your illustrations and your story have started my day on a good note!
I had read These Truths by Jill Lepore, which was a good overview of American History for someone not big into history. I liked her writing and read The Secret History of Wonder Woman. I found that fascinating and entertaining.