Your nose won’t grow when you tell a lie, but it can still give you away. According to University of Granada researchers, the “Pinocchio effect” causes your nose to get warmer whenever you think about being dishonest.
The Spanish researchers asked 20 college students to answer questions like “Have you ever been caught cheating on an exam?” or “Have you ever had sex in an elevator?” and instructed 10 participants to fib half the time. Using thermograms — images produced by measuring the amount of radiation emitted by an object, which increases as its temperature rises — the researchers discovered that lying had a big effect on nasal temperature. “It rises during lie planning, due to mental effort or anxiety, and drops during the act of lying, probably due to [the subject hoping to be believed and looking for] empathy,” researcher Emilio Gómez Milán speculates.
Thermograms were first used by the United States for WWII surveillance. And today thermal imaging can help detect breast cancer, monitor volcanoes, or even fit a horse saddle. The study is the first to discover psychological uses, however.
In a paper describing the study, the scientists imagine that their findings could help make the world a more honest place. Who knows? Maybe someday you’ll be able to tell which politicians are telling the truth and whether or not your spouse really likes your new haircut.