But, according to numerous studies, polygraphs cannot reliably detect lying, or truth-telling, and their use in the justice and employment systems is regulated due to those problems with scientific reliability. A landmark 2003 report from the National Academies of Sciences, Engineering, and Medicine found the quality of research about polygraphy to be low, the theoretical explanation of how it functions (and why it detects lying, and not, say, nervousness) to be inadequate, the rate of false positives to be unacceptable, and the rate of false negatives to be a risk. Researchers still cite this study. //

But if media audiences find themselves in a polygraph exam room, they should probably feel twinges of doubt, perhaps especially if they are innocent. Citing evidence from William G. Iacono, a professor emeritus of psychology at the University of Minnesota, he said that polygraphs can identify just 75 percent of guilty people. But critically, they only accurately judge truth-tellers around 57 percent of the time. “The research generally shows that the people who are innocent are at a disadvantage,” he said. //

Of the 36 cases with a definitive polygraph examiner judgment, a correct exculpatory outcome only occurred in eight cases. But Denkinger’s issues with the dataset went further: “Every single person who took a polygraph in the set was done a disservice by the polygraph,” he said. “Either they were told they failed because the examiner thought that the result was a deceptive response, which was a false interpretation, or they were truthful, and the interrogators or the examiner misrepresented the result and told them that they were lying.”

That latter part is the focus of Denkinger’s most recent work: how the polygraph is used coercively. For example, law enforcement is permitted to tell subjects they’re failing the polygraph even if they’re not—a practice that can induce false confessions. And it is confessions that law enforcement is after. //

At the University of Utah, where he got his doctorate, Honts developed a method of polygraph examination that used standardized questions and relied less on the expertise of the examiner. He says that unlike some other countries, examiners in the US haven’t adopted the methods he sees as best-practice at a large scale, in large part because they see polygraphs more as interrogation tools than lassos of truth.

That practice can let guilty people go free, send innocent people to court, and make the most sensitive parts of our government—the defense and nuclear establishments, which both use polygraphy to vet employees—less secure. For instance, infamous spy Aldrich Ames, a three-decade CIA employee who passed secrets for close to a decade prior to his arrest, to the Soviets and later the Russians, passed a polygraph twice while actively committing espionage. Ames later said his polygraph savvy was aided by advice from the KGB, who told him to be cooperative and stay calm to pass the examination. //

Scientists like Lee may be getting closer to an accurate lie detector, and improving on the traditional polygraph. But there’s currently no superhero solution. And the problem, as Lee’s research hints, may be ontological, not technological.

That’s definitely Maschke’s view. “It’s all pseudoscience,” he said. “There is no lie detector. So my thinking is that it’s better not to pretend that you can detect lies, because it’s a way of deceiving yourself.”