Just Like Pinocchio, Your Nose Knows When You're Lying
When you tell a lie, the temperature in your nose increases. This is called the Pinocchio effect.
Liar, Liar, Nose On Fire
When we were kids, Pinocchio was something of a cautionary tale: tell a lie, and your nose will grow. Keep fibbing, and you'll soon sprout a branch from the middle of your face. Not exactly science, but the story at least scared you into admitting when you stole your little brother's toys. Turns out, your nose actually does know when you're lying. It doesn't grow (phew!) but according to a study conducted by researchers at the University of Granada, the temperature of your nose increases in response to telling an untruth. (It happens to your inner eyes too.) Using thermal imaging, which basically allows scientists to see small increases in body temperature with a heat-sensing camera, the researchers studied people's faces when they were lying. "When we lie...the temperature around our nose raises and a brain element called 'insula' is activated," according to a press release about the research. "The insula is a component of the brain reward system, and it only activates when we experience real feelings." In this case, the "real feelings" they're referring to are the anxiety a person feels about telling a fib, and the mental effort it takes to conjure up an intricate lie.
How To Spot A Liar
The researchers don't specify just how much the temperature of the nose increases when you're lying, so don't go grabbing your colleague's face the next time she mentions she's "coming down with something" in the office. Given that they used thermal cameras, it's not likely that her nose will scorch your hand. You're better off using some easier-to-pull-off techniques, like observing a person's body language. As Dr. Lillian Glass explains in her book The Body Language of Liars, if a person's breathing gets heavy, they start repeating themselves, or they cover their mouths as they talk, you might do well to question their honesty. Or, you know, grab their nose. Because that wouldn't be weird.
Watch And Learn: The Lying Game