Psychology researchers from the University of Granada in Spain used thermography to study the temperature of people's faces
in experiments. They said they found a jump in the temperature around
the nose and in the orbital muscle in the inner corner of the eye during
lying. They also found that face temperature drops for people
performing a difficult mental task and rises for people experiencing
The researchers used a thermal imaging device to figure this out, but if it's true there may be a foolproof way to tell when someone is lying. If someone's nose really does heat up when they tell a lie then you should be able to put your mouth around their nose and feel the temperature of their nose with your tongue. The trick is to train yourself to sense slight changes in temperature with your tongue BEFORE you start sucking shady people's noses. Just don't forget to taste their nose when they haven't been lying to get a baseline to differentiate when a lie may be occurring or when someone is telling the truth.
If this lie-catching method catches on then you might see liars eating a lot of peppers to make their noses run so people are less likely to want to suck on them to tell if they're lying. You're going to need to take things like that into consideration and be wary of people with bad sinuses and allergies, these may be the worst liars of all and the price to tell will be high.