The liar’s brain. How does it work and how does it differ from others?

The liar’s brain. How does it work and how does it differ from others?
Publication date:
It takes approx. 4 minutes to read this article

Lying is an integral part of life in all areas of life – everyone lies, for all kinds of reasons and about many topics. And even the smallest untruth forces the brain to work hard.

Everyone lies. Most often teenagers between the ages of 13 and 17 (an average of three times a day), and least often older people 60-77 years and young children 6-8 years (just over one and a half times a day). So it turns out that people are most likely to lie at the age when it comes easiest to them. That is, when the brain is most agile and can do more of the work that lying requires of it in less time.

The truth is less complicated

And it’s not about moral considerations, but pure physiology – telling the truth doesn’t tax the brain the way lying does. Dr. Pheroz Mohammed of Philadelphia conducted an experiment involving 11 people – during an MRI scan, some had to lie and others had to tell the truth. When the participants lied, 14 areas in their brains worked simultaneously, and when they told the truth 7.

The same areas in the brain are responsible for lying as are speech, attention, and decision-making. When a person lies, the prefrontal cortex, inferior parietal lobe, anterior insula, and medial superior frontal cortex, among others, are actively working. The brain works more intensely because it has to simultaneously hide the truth, make up untruths, and remember and sort it all.

When lying becomes a habit

The more often we lie, the faster our brain works: pathological liars have 14.2% less gray matter, but 22% to even 26% more white matter, or nerve fibers. This allows them to more quickly connect facts to lies and build coherent stories. It has also been proven that the brain becomes accustomed to lying and over time stops reacting to it, which is linked to the suppression of the amygdala responsible for emotional reactions such as guilt or fear.

When a person cheats for the first time, the amygdala is activated and the liar feels anxious. However, continually telling an untruth causes the brain to treat it neutrally and the person over time stops feeling fear, anxiety or remorse. This makes pathological liars able to fool even lie detectors.

The body’s reaction to lying

Lying is not only noticeable in the workings of the brain. The whole body reacts to passing the truth. First of all, the level of cortisol and testosterone rises sharply. The former is a stress hormone that helps relieve emotional tension. The second hormone helps get rid of the feeling of fear that the deception will come out.

Lying also raises body temperature. If a person lies, the skin around his nose becomes warm, and Reil’s islet, an area in the brain involved in controlling body temperature, is activated. Scientists have called this phenomenon the Pinocchio effect.

It is worth noting that liars are more likely to suffer from depression, complain of headaches and have trouble sleeping.

Why do we lie?

For a variety of reasons. In one study, the largest number of respondents – 22% – admitted to lying to cover up their own mistakes or misdeeds. Slightly fewer indicated that they usually lie to obtain some benefit, and to avoid meeting unpleasant people (16%, 15% and 14% respectively). For 8% of respondents, lying is a way to make a good impression on others. A small number of respondents also mentioned politeness, jokes, wanting to please others, avoiding an argument, or answering uncomfortable questions. 7% admitted to not knowing why they lie, and for 2%, lying appeared to be a pathological condition.

Main photo: David Cassolato/

Add comment

Your email address will not be published. Required fields are marked *


1 × 3 =