Pity poor Pinocchio. The wooden boy of legend always had to tell the truth – otherwise his nose would grow longer and give away the fact that he was lying.

Well, soon we may all be living in a world where our bodies will betray us when we’re telling a fib. But a casual observer won’t be able to tell. It will require special equipment to monitor what happens in the brain and body when we lie.

When I heard this, the first thing I thought of was old-fashioned lie detectors, which are totally unreliable, easy for people to fool, and an all-around fraud as far as I’m concerned.

But now it looks like scientists are on the verge of a lie detector that works. It all depends on what goes on in your brain when you lie. . .

The Reverse Pinocchio Effect

Although Pinocchio’s wooden nose got longer each time he told a lie, researchers at the University of Grenada say our noses actually get a little smaller when we tell a falsehood.1

The researchers call this a “reverse Pinocchio effect.” Besides your nose slightly shrinking, they say, brain activity causes the temperature at the tip of the nose to dip by up to 2.2 degrees Fahrenheit. And while that’s going on, your forehead gets slightly warmer.

“One has to think in order to lie, which increases the temperature of the forehead,” says researcher Gomez Milan. “At the same time we feel anxious, which lowers the temperature of the nose.”

When the people in this experiment made phone calls to relatives and told a pretty big whopper, thermal cameras were able to detect temperature changes in their noses and foreheads 80 percent of the time – a better rate of success than modern lie detectors, according to the researchers.

But the Grenada researchers aren’t the only ones looking into how to detect lies.

Brain Scans as a Lie Detector

Scientists at the Perelman School of Medicine at the University of Pennsylvania have announced that scanning your brain with an fMRI (functional magnetic imaging) captures brain activity that can also be used to detect lies.2

These researchers explain that when you lie, parts of the brain involved in decision-making are activated – and scans show these areas light up with activity in ways that reveal lies are being told.

In the Pennsylvania tests, when the fMRIs were compared to polygraph lie detector results, the fMRIs came out 24 percent ahead in detecting falsehoods. (I’m still not that impressed, but we’ll see. . .)

The fMRI advantage, says researcher Daniel D. Langleben, stems from the fact that what a “polygraph measures reflects complex activity of the peripheral nervous system that is reduced to only a few parameters, while fMRI is looking at thousands of brain clusters with higher resolution in both space and time. While neither type of activity is unique to lying, we expected brain activity to be a more specific marker, and this is what I believe we found.”

How to Tell if Someone is Lying

Researchers are not only examining ways to distinguish lies by using brain scans and thermal imaging. They’re also studying how to make all of us better at telling when someone is lying.

Investigators at the University of California – Santa Barbara warn that most of us are terrible at telling when somebody is lying. Previous studies have demonstrated this. I had to laugh a few years back when an acquaintance of mine told me he could tell when someone was lying. Nonsense.

If you think people are being deceptive when they fidget, look up down and all around (instead of at you), and tell elaborate stories, these scientists say that taking note of those mannerisms is pretty worthless when it comes to lie detection. Actually, in my experience, good liars don’t do any of those things, while many honest, moral people are just shy and nervous and do all of them.

As a more effective approach, these academics have come up with a video game called VERITAS (Veracity Education and Reactance Instruction through Technology and Applied Skills) that can train you to notice the real signs that a person is lying.3

According to this research, liars:

  • Repeat themselves a lot as they try to keep their lies consistent and remember the lies they’ve told.
  • Wait longer to answer questions and repeat the questions before they answer because they are working hard to keep their story straight and invent details.
  • Show signs of uncertainty – “A lack of embracement of their story,” says researcher Norah Dunbar.
  • Stay tense, rigid and stiff without making gestures – An unnatural “freeze mode” as though they’re trying not to show anything.

The researchers note that law enforcement personnel have used the VERITAS game to improve their ability to tell when people are lying to them – improving their accuracy up to an average of 78 percent.

I’ve no doubt that these tips are useful when applied to people who are generally good or at least have a conscience. I doubt if they will work with sociopaths and professional con men who don’t have a conscience, are not bothered the least by lying, and also have had a lot of practice at it. They lie for a living. They know how to do it.

And that means your personal “lie detector” will fail you when you need it most.

So beware. . .

One final note on lying – If you want to improve the odds that somebody is telling you the truth, a study in Finland shows that keeping eye contact may significantly increase the chances the person talking to you will not lie.4 But the Finn researchers warn that their results were achieved in “experimental circumstances,” so they may not be as reliable in real life.


  1. https://www.ncbi.nlm.nih.gov/pubmed/28714186
  2. https://www.ncbi.nlm.nih.gov/pubmed/26794034
  3. https://www.researchgate.net/publication/323937871_Reliable_Deception_Cues_
    Training_in_an_Interactive_Video_Game
  4. https://www.ncbi.nlm.nih.gov/pubmed/30408602