Smithsonian.com

A thermal image of a lying subject gives away his bright red nose. Photo: The University of Granada

Like Pinocchio, when a person lies, their nose reveals the fib, new research shows. The area on and around the nose increases in temperature, giving away the anxiety lurking below the surface of an otherwise cool facade. This increase in temperature also occurs when other mental efforts are at play, such as performing a difficult task or being rigorously interrogated.

A brain element called the insula triggers this reaction. This part of the brain plays a role in detection and regulation of body temperature, the researchers write, and is also linked to emotional feeling. Local temperature changes, they found, are associated with the physical, mental and emotional state of their subjects. In a way, the researchers think that a person’s thermal state lends insight into what he is feeling or thinking.

When it comes to telling lies, the research subjects’ noses lit up with a bright red flush. While this change is less obvious than Pinocchio’s extending nose, it turns out our faces do give us away when we’re trying to pull a fast one, in a way more akin to Rudolph the Red-Nosed Reindeer.

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