We learn to lie around age two or three. By the time we’re adults, we do it a lot-at least once a day, and perhaps more like 2.92 lies in 10 minutes, according to a recent study published in the Journal of Basic and Applied Psychology. It’s no wonder we’ve been chasing after an accurate lie detector for so long.

In fact, we’ve been aiming at ways to expose the lies and the liars who tell them for a long time, and it’s never been easy.
Two thousand years ago in India, someone suspected of lying was asked to chew a grain of rice. If, after some directed mastication, the subject could spit the rice back out, the truth teller was in the clear. If they couldn’t reproduce the grain, it was assumed that the accused’s mouth went dry from fear of being found out and he chomped the rice to dust.

As far as fib-finding devices go, we’ve come a long way. The first machine-powered lie detector was the “systolic blood pressure test” created by the Harvard psychologist William Mouton Marston in 1913. If that name sounds familiar, it’s because Marston’s best-known creation is actually Wonder Woman. But Marston’s real-life lie-detector was not just a lasso that made you tell the truth. It worked like this: While asking a series of questions-What is your favorite color? What did you eat this morning? Did you murder your coworker?-Marston would take a subject’s blood pressure. An elevated reading associated with an answer pointed to the subject’s guilt. With just a rubber tube and that cuff a doctor inflates around your arm, Marston claimed to be able to tell the truth tellers nearly 100-percent of the time. Riiiight. And you have an invisible plane too…

By 1921, the PhD forensic scientist and police officer John Larson found a way to take the question, blood pressure recording, question, blood pressure recording system up a notch by making the process continuous. Instead of measuring blood pressure piecemeal as subjects answered yes or no, a reading could be taken the entire time, which is more like what we think of when we think of polygraphs today: little seismic readings dictated by our own guilt and deception.

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