Depicted above is Pinocchio, in this case, from the 1940 Disney movie. Pinocchio, if you’re somehow not familiar with him, is a sentient marionette made of wood, paint, and love. His one dream is to become a “real boy” and to get there, he believes he has to be a moral, upstanding citizen of the world who is worthy of such transformation. And to make it easier for him to do that — in a roundabout sort of way — Pinocchio comes with a little feature: if he lies, his nose grows, as seen above. And it’s hard to lie when your nose grows when you do.
For those of us in the real world, that doesn’t happen — you can lie without anyone noticing a change in your nose. But that’s probably because they don’t have the right equipment. Because it turns out, when you lie, your nose likely knows it.
There is no perfect lie detection device. The polygraph, which is most often called a “lie detector,” has been around for decades, but doesn’t detect lies directly, if at all. Polygraphs measure changes in blood pressure, breathing rates, pulse, and other physiological factors. In theory, lying causes many of us to feel some degree of anxiety, and that anxiety should (again theoretically) be reflected in subconscious changes that can be picked up by such a device. That’s certainly possible, but it’s not something that you can rely upon when determining truth from lies is critical. So the science community has kept on looking for better ways to tell if someone is fibbing. About twenty years ago, researchers developed test using Functional magnetic resonance imaging (an “fMRI”) to look at people’s brains as they were lying. Scientific American explains:
An fMRI machine tracks blood flow to activated brain areas. The assumption in lie detection is that the brain must exert extra effort when telling a lie and that the regions that do more work get more blood. Such areas light up in scans; during the lie studies, the illuminated regions are primarily involved in decision-making.
The test isn’t the most accessible — fMRI machines are expensive and cumbersome — and the test is also apparently beatable. But it’s reliable enough for use in clinical studies and can give other researchers a baseline way to see if test subjects are lying. And that’s where Pinocchio comes into the picture — because it turns out, your nose knows you’re lying.
For years, researchers Emilio Gómez Milán and Elvira Salazar López from the psychology department at the University of Granada have been using thermal imaging — basically, heat-vision cameras — to detect changes in blood flow and skin temperature in various situations. They’ve had some notable success, particularly in what could be considered R-rated thoughts involving R-rated body parts, and in 2012 — perhaps inspired by Pinocchio — wanted to test the effect of lies on noses. They pointed thermal cameras at test subjects while also measuring the subjects’ brain activities in the fMRIs to see when they were lying. The results, as Vice explains, suggest we’re all secretly related to the wooden marionette of lore:
By monitoring people’s skin temperature with a special heat-sensing camera (think Predator vision) and asking them questions about subjective experiences, feelings, and emotions, the psychologists were able to discern the truthiness of people’s responses. It turns out that when we lie, blood rushes to the center of our faces. If you’re behind the lens of a thermography camera, the lies light up our noses and the inside corners of our eyes.
And, to further make the Pinocchio connection, the researchers noted that only the nose and below-eye regions show this effect. In fact, per Vice, “not only do our noses brighten when we’re fibbing, but the other areas of our faces — cheeks, chins, foreheads — cool down,” as seen in the image below (via Popular Science).
Like most lie detection efforts, this one hasn’t been reliably deployed in a meaningful way. A 2018 follow-up study (by the same researchers) suggests that the “Pinocchio effect,” in the words of their university, is “the most reliable scientific model to date for detecting when a person is lying” known to date. But for now, those results have only been established in a laboratory setting. And ultimately, there may be no way of ever developing a perfect lie detection test. As the authors of the study note in that University of Grenada article, “the difference between truth and lie is quantitative, not qualitative,” and therefore, impossible to fully measure objectively.
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