Any moral preoccupation aside, whether we realize it or not, we lie, a little more or a little less, every day.
But what happens in your brain when you knowingly lie to someone? And how do you know that someone is lying to you?
When someone tells the truth, an alternative cognitive process occurs, the active areas in the frontal, limbic and temporal system are fewer, because it is not about inhibiting the truth or expressing anxiety. However, when the person is lying:
- The frontal lobe is activated, it helps to erase and inhibit the truth
- The limbic system is racing, contributing to increased anxiety caused by lying
- The temporal lobe activates to check the accuracy of the invented mental image
- Eye movements to the left during a lying speech, reveal the invention of facts (smell, image, sound, depending on the direction of the gaze).
Some studies have shown that compulsive liars have 26% more white matter in their prefrontal cortex, allowing them to make a better connection between ideas that are not actually connected in reality. For example "I am" and "a fighter pilot"
Most people lie once or twice a day, men and women lie as much as each other. A fifth of the exchanges lasting more than 10 minutes contain at least one lie.
27% of physicians lie in their profession (less than 77% lawyers, celebrities and executives 92%). - Source:
1- RSNA radiology (brain mapping of deception and truth telling, functional MRI & polygraph investigation)
2 - British Journal of Psychology (prefrontal white matter in pathological liars)
3 - NPR (Brain scan to see lies)
