There is no such thing as a LIE DETECTOR

liarDespite heroic efforts to find the holy grail of TRUTH, science has never effectively found a way to detect deception. There are of course polygraphs and it’s well known that they are inadmissible in court virtually everywhere as substantive evidence of deception. There’s a reason for this, and it is well documented at sites like, where the “junk science” behind these machines is exposed and effectively debunked. Why, then, does the FBI still routinely use them to interview suspects and employees, and why do so many law enforcement agencies use them during investigations? Simple. They provide a convenient cover for what is really an interrogation. The FBI will tell a suspect that they plan to administer a polygraph to “clear the suspect” and, instead of the typical 3-5 question session, they go on for six to eight hours with questions that far exceed the scope of any standard polygraph, and are really just used to justify further questioning (“the machine says you’re lying, and machines don’t lie”).

But the search for truth continues and scientists continue to explore the concept of a reliable method of detecting deception. One recent development is the notion of capturing “micro-expressions”. The idea here is that our initial reactions to news or questions, causes involuntary physical reactions that we cannot consciously mask, even if they only last micro-seconds. If we can capture these initial slices of human behavior, so the theory goes, perhaps we can find some uniform reactions that reliably reflect deception. It sounds like a real stretch to me, and at the end of the day someone is still going to have to make some kind of subjective judgment call as to what physical reactions reflect deception, but it does seem like something that could be empirically tested, so the application of a rigid scientific methodology in validating this hypothesis is welcomed.

But don’t get your hopes up. Or your fears. Read more in this New Yorker article.

– RP