How to tell if someone is lying?

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When someone lies or is prevented from telling the truth, activity is observed in the brain that stimulates blood flow to the prefrontal cortex (above the eye socket). Lying is a response of executive function because it requires concealing the correct answer and giving a different response instead. If you know the answer to a question and you are going to tell the truth, it comes automatically, but concealing the correct answer and trying to give a different response requires a different function, says Prof. Dr. Sean Spence from the adult psychiatry department at the University of Sheffield, UK.

 

Building on the importance of the prefrontal cortex in previous studies, Yang and colleagues imaged the prefrontal cortex of 49 people who lied and those who didn't. When you look at this part of the brain, you see gray and white matter. In this study, it was found that those who lied had an average of 25% more white matter in the prefrontal cortex compared to those who didn't lie. According to Yang, the increase in white matter is because those who lie consistently and compulsively form more connections in their brains related to untrue thoughts, and there is growth in that region.

Harvard neuroscientist Lawrence Farwell says that a specific brainwave called P300 is the brain's fingerprint for detecting lies. Photographs are shown on a computer screen while electrodes are attached to the person's head, and the P300 is activated when a familiar object is encountered. This technique shows us whether that information exists in the brain, says Farwell. He adds that this technique was used by the CIA to find moles. Furthermore, Farwell's technique was used by an Iowa court, which considered it sufficiently scientifically proven, to determine whether a suspect was guilty.

In fMRI studies by another Harvard professor, Kosslyn, the activated region in the brain of those who lie spontaneously and without preparation is not the same as the activated region in those who lie based on a scenario over a certain period of time. In spontaneous liars, the area in the back of the brain responsible for visualization and bringing things to mind is activated along with the anterior prefrontal cortex. This is thought to be because those who lie impulsively need to visualize whether the story they're making up makes sense.

What are some observable differences in someone who is lying?

While there's no solid evidence, there are clues that might raise suspicion. Avoiding eye contact is one example. When someone is talking to you, they usually make eye contact for at least half the time. If they avoid eye contact or look down during a conversation, they may be lying. Another sign is a change in tone of voice. Fluctuations in voice pitch and speed can also indicate lying. Body language—covering the face or mouth, inability to sit still, constant hand or leg movement—can also be a sign of deception. Incoherent speech and contradictory statements can also raise suspicion.

How should you approach a child who is lying?

Many children lie during their developmental stages. Learning to lie is as much a stage of their development as learning to tell the truth. Children often lie to get attention, to cover something up, to gauge their parents' reactions, or to manipulate a situation.

Children usually begin to lie between the ages of 4 and 6, although they may lie before the age of 4, but in these cases, it can be described as using their imagination more and telling exaggerated stories, such as describing an event that didn't happen as if it did. Even if 4-6 year old children lie, if you press them and question them in more detail, they will begin to tell the truth.

According to studies, adults may lie at least once a day, a 4-year-old child every 2 hours, and a 6-year-old child every 90 minutes.

The number of lies may increase during school age, and from the age of 8, they may lie more professionally without being caught.

To prevent your child from lying, talk to them about how important honesty is. You can even tell stories about children who lie and honest children who don't, emphasizing the importance of honesty.

You can tell your child that you will be very upset and disappointed if they lie, and that you don't want that to happen.

If you clearly define what is acceptable and unacceptable at home and set rules, your child will act according to what is acceptable.

When your child is honest with you, praise them, tell them how much you love them, that you are proud of them for being honest, and emphasize the importance of honesty.

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If your child lies and you find out, explain that lying is unacceptable, that you don't like it, why it's wrong, and that it will be difficult to trust them anymore. Then, give them an appropriate punishment. Don't joke or laugh when they lie.

You can investigate the underlying reason for their lying and act accordingly. For example, if they are trying to get your attention by lying, you may need to work on that.

Don't directly say things like, "You're a liar, you're lying to me, did you lie again?" Instead, focus on the importance of honesty, saying things like, "There's a problem here, it would be better if you told the truth, you should be honest with me, honesty is very important."

Furthermore, in my studies with children who lie, we detect electrical current disturbances in the frontal lobe of the brain, supporting findings from research. When we teach them to regulate these electrical current disturbances using EEG biofeedback, the children begin to realize that lying is wrong and stop lying.