Lying causes you to imitate the body language of your interlocutors, according to this study

Dutch researchers recently determined that lying unconsciously causes us to mimic the body language of our interlocutor. A discovery that could potentially lead to the development of new approaches to detect it.

Revealing experiences

For this study published in the journal Royal Society Open Science, Sophie van der Zee and his colleagues fromErasmus university of Rotterdam asked about 50 students to solve a puzzle in 5 minutes. Described as simple, this one was actually impossible to complete in the allotted time. Van der Zee had ” hidden “Solutions in the room, so that subjects could easily find them and be tempted to cheat, and asked the students not to reveal to her supervisor that the solutions had been” accidentally Forgotten in the room, evoking possible professional repercussions.

The researchers then recorded interviews in which each subject was invited to discuss in front of another student the challenge of the puzzle, which, if they complied with the request of Van der Zee, involved lying about how they solved it.

Using a wireless accelerometer, the team recorded the movements of the head, chest, and hands of the students (speaker and interlocutor), and found that when a subject was telling the truth, their body movements differed from those of the individual facing him. Conversely, when the subject was lying, the movements of the two people tended to align.

According to the authors of the study, this could be explained by the fact that lying requires great concentration. Copying requires less thought than inventing one’s own body language, so speakers would unconsciously imitate the most subtle bodily movements of the person in front of them. Difficult to detect with the naked eye, this way of facing the ” cognitive overload Was detected thanks to the accelerometers.

An unconscious tendency

” People who lie often deliberately change their behavior in order to act as those who tell the truth would be likely to do, but this tendency to imitate the interlocutor is something unconscious. “, has explained Van der Zee. ” Which could make it an interesting clue to detect the lie. “

However, the researchers themselves admit that the results of the accelerometers do not make it possible to determine which of the speaker or interlocutor is copying their body language on that of the person facing them.

” This is fascinating basic research providing interesting avenues for possible future use in trials, if this is validated by further studies. “, commented Tim brennen, of the’University of Oslo.