When the wooden Disney character Pinocchio lied, his nose grew. Turns out there is some merit to your nose giving away clues about when you're fibbing.
A study from researchers at the University of Grenada in Spain used thermal imagery to study a person when they lie. The study found when a person tells an untruth, the area around the nose heats up -- registering a hotter color in the thermal image. They call this "Pinocchio effect."
This image shot with a thermographic camera shows how the area around the nose will be hotter when someone is telling a lie. (Image: Emilio Gómez Milán and Elvira Salazar López/University of Grenada)
According to the university's website, lying about one's feelings affects a part of the brain called the insula. It states the insula activates when one experiences "real feelings."
"The insula is involved in the detection and regulation of body temperature. Therefore, there is a strong negative correlation between insula activity and temperature increase: the more active the insule (the greater the feeling) the lower the temperature change, and viceversa," the researchers stated.
They found that lying is not the only thing that will change the temperature in the face but also strong mental exertion, which drops temperature, and anxiety, which raises it.
Live Science pointed out this work was performed as part of a doctoral thesis and has yet to be published in a peer-reviewed journal.