A hand gesture that comes a second too late, a voice that rises a notch, an "honestly" slipped in at the wrong moment... The body of a dishonest person often reveals what their words try to conceal. Here’s how to spot these signals and verify a doubt without falling into systematic distrust.
To recognize a manipulator through body language, one must first identify the discrepancy between what the person says and what their body expresses at the same moment. A manipulator may carefully choose their words, but their gestures, facial expressions, and voice often do not align with the narrative.
Why does the body convey so much? Research conducted at the University of California, Los Angeles (UCLA) has estimated that only 7% of the meaning of a message is conveyed through words, compared to 38% for tone of voice and 55% for body language. A simple blink, almost imperceptible, can signal that a statement is ironic and means exactly the opposite of what it claims.
Observing before defending oneself is also a matter of reciprocity. Experienced individuals know how to notice the small hesitations of a conversation partner, those gestures that betray a temporary loss of confidence, and can exploit them to their advantage. Learning to read the body language of others helps you avoid being misled by reassuring speech (even when the person insists otherwise) and allows you to better control what your own body reveals.
Body language refers to the set of signals transmitted, whether intentionally or not, through posture, gestures, facial expressions, and movements. The work of observation involves calmly noting these signals without jumping to conclusions: a sign taken in isolation proves nothing; it is its contradiction with the words that should raise your suspicions.
On average, people lie once or twice a day: this is suggested by numerous studies conducted among Westerners. Other research suggests a higher figure, at least seven lies per day for both men and women, provided that "white lies" are also counted.
A white lie is one that is told to preserve the relationship, without harming anyone. The classic example? "That dress looks great on you," when it really doesn't. This little arrangement with the truth mainly serves to avoid brutal, and perhaps unnecessary, honesty in order to maintain good relations with others.
This observation is thought-provoking for those who boast of being perfectly honest: all human beings have the capacity to lie, and no one completely escapes it. The real question is not whether a person lies sometimes (that's almost certain), but distinguishing polite lies from those that can have unpleasant consequences, both at work and in private life.
Moreover, lying is not equally easy for everyone. The difficulty varies according to the experience and personality of the liar, and certain situations can even push a dishonest person to betray themselves: when the stakes are high, the tension rises, much like at a gaming table. If the penalty for being caught is severe, even the most skilled liars struggle to maintain control over their words and body signals.
To establish the baseline behavior of an honest person, observe them as they respond to trivial questions with no stakes, such as "Where are you from?" This is the method recommended by Traci Brown, a body language expert who regularly works with financial institutions to help employees detect and prevent concealment: before looking for signs of a lie, one must know how the person behaves when telling the truth.
Specifically, the method unfolds in two stages.
First stage: ask a few neutral questions and note what you see. Where do their eyes go when they think? How does their voice sound—deep or high, fast or measured? What do their hands do while they speak?Second stage: once this reference is firmly in mind, watch for changes in behavior when the conversation touches on the sensitive topic.
This baseline behavior explains why it is easier to "read" people you know well. When you have known someone for a long time, you recognize their expression when they are trying to remember something and how it changes when they are fabricating. If they are telling the truth, they respond without hesitation, with that familiar look. If they are lying, they hesitate and look elsewhere.
The baseline behavior thus serves as a point of comparison, nothing more, nothing less. A naturally fidgety person who moves their hands a lot when they talk is not necessarily lying when they fidget. Conversely, someone who is usually calm but suddenly starts scratching or changing their voice deserves a bit more attention.
The signs that reveal a lie fall into four categories: body movements, facial expressions, tone of voice, and content of speech. According to Dr. Lillian Glass, a body language expert, these four categories essentially form the codes of communication, where one should look for changes compared to the person's usual behavior.
Here’s what each category looks like, with concrete examples:
Body movements: hand gestures, fidgeting, rocking back and forth, crossed arms, feet that can’t stay still.Facial expressions: eyes that divert or fixate at a crucial moment, bitten or pursed lips, sweating on the forehead or above the upper lip.Tone of voice: a voice that becomes high-pitched, that quivers, that suddenly increases in volume, throat clearing.Content of speech: phrases like "honestly" or "to be honest," filler words like "kind of" or "mmm," hesitations and pauses.
These categories overlap with the major families of non-verbal communication. Gestures and facial expressions fall under kinesics, voice under paralanguage (everything that modifies the sound of the voice), and the use of space under proxemics. On this last point, a liar tends to avoid direct physical contact and keep their distance to avoid risking exposure.
However, it is important to note that these signs are not infallible. An uncomfortable person may fidget, and a nervous person may naturally change their voice without hiding anything at all. It is the change from baseline behavior, especially when it touches multiple categories at once, that lends weight to the observation.
Among the signs of the body that betray a liar, hand gestures and movements come first: in a person who is lying, they often occur after the statement instead of accompanying it, and the palms tend to be hidden. The rest of the body (head, shoulders, arms, feet) completes the picture, provided one knows what to look for.
The delay of the hands can be explained by the overload of the mind, busy inventing a story, judging its credibility, and adding details as it goes along. A study from the University of Michigan, conducted in 2015 on 120 videos of high-stakes court cases, also showed that liars move both hands more: this was the case in 40% of lying instances, compared to 25% for those telling the truth. As for hidden palms, body language expert Traci Brown sees it as an unconscious signal of a person withholding information and emotions.
Other gestures to watch for:
The nose: touching or scratching it repeatedly. Tension raises blood pressure in the nose, cells release histamine, causing itchiness, hence this typical gesture.The mouth: covering the mouth, touching the lips or chin, or even placing an object in front of the mouth.The head and shoulders: tilting the head to the side, or pulling it into the shoulders when mentioning the issue.The arms: crossed arms, a sign of a defensive person trying to protect themselves from an uncomfortable situation, like the revelation of their lie.Hands on the body: stiff, tense, and repetitive movements on the arms or legs, fingers playing with hair.The whole body: fidgeting, scratching, rocking back and forth, playing with feet.
Finally, observe the rhythm of movements. Sudden quick movements indicate discomfort or anxiety about the situation, while an action performed very slowly may be a way to try to conceal something. A change in tempo compared to the person's usual pace is often more telling than the gesture itself.
In body language, the definition of adapters is simple: they are learned movements for adaptation, serving to satisfy a physical or psychological need, or to maintain contact with others. Examples of gestures include scratching when the skin itches, rubbing one's legs for reassurance, fiddling with an object, smoothing one's beard, or bringing fingers to the nose under tension.
The concept comes from kinesics, the study of movements, gestures, postures, and facial expressions through which the body communicates. Researchers Paul Ekman and Wallace Friesen identified five main categories: emblems, illustrators, affect displays (expression of a state of mind), regulators (unconscious signals that organize turn-taking in conversation), and finally, adapters.
Why do adapters betray discomfort? Because they provide relief. When a person is nervous, variations in their autonomic nervous system (which regulates bodily functions without conscious thought) can cause itching and tingling, leading to increased agitation. Rubbing one's legs back and forth is a typical self-soothing gesture that clearly indicates discomfort at that moment. The same goes for someone who airs out their shirt or plays with their thumbs while being questioned: beyond a potential hot flash, these small gestures may signal a problem, discomfort, or insecurity.
Some of these gestures even become tics, appearing suddenly to manage tension and then becoming established: uncontrolled blinking, cheek contractions, jaw displacement to the side, bitten tongue, fingers repeatedly going to the nose or eyes. These behaviors are relaxing (which is why we develop them; the brain experiences them as a form of soothing) and tend to worsen, even accelerate, under stress. An acceleration during a conversation is therefore more revealing than their mere presence.
Illustrators and emblems are two families of gestures in non-verbal communication, and their difference lies in their relationship with words. Illustrators accompany speech to provide a visual image, while emblems translate directly into words and can replace a phrase.
An emblem has a conventional meaning, shared by a culture, group, or social class. It serves to repeat or replace speech, making it very useful when the interlocutor is far away or when the environment is noisy (think of the head shake indicating "no" directed at someone across a room). However, caution is advised: the meaning of gestures varies by country, its history, and how its inhabitants have grown up, and a gesture that is mundane for you may mean something entirely different elsewhere.
In a dishonest person, these two families of gestures become noticeably disordered.
Illustrators arrive late: normally, the hand accompanies the phrase, either before or during its utterance. In the liar, the gesture occurs rather afterward because their mind is occupied with the story they are inventing.Emblems contradict words: someone may assert, "I slept outside because of work," while subtly shaking their head "no." Their body does not confirm what their voice is saying.Gestures disappear: a person who remains completely still while speaking appears stiff, unnatural, and gives the impression of wanting to hide their emotions.
Nota bene: kinesics is the discipline that studies communication through body movements. Its founder, American anthropologist Ray Birdwhistell, filmed people in social situations to analyze their gestures and believed that all body movements carry meaning, with their own grammar. However, he rejected the term "body language," arguing that the body does not convey a language in the sense understood by linguists.
When we lie, expressions of fear or anger can escape involuntarily, sometimes in a fraction of a second. This is known as affect-display: the movements of the face or body that reveal a state of mind, which can only be identified by knowing the specific traits of each emotion.
Traits to recognize:
Fear: raised and drawn-together eyebrows, often in a flat line, wrinkles on the forehead between the eyebrows, raised upper eyelid, white of the eye visible in the upper part but not in the lower part, open mouth with slightly tense or pulled-back lips.Anger: lowered and drawn-together eyebrows, vertical wrinkles between them, fixed or bulging eyes, stretched lower lip, lips sometimes pressed firmly together with the corners turned down, nostrils sometimes flared, lower jaw thrust forward.
The fear of being discovered also produces more diffuse signs. Changes in the autonomic nervous system can cause sweating in the T-zone of the face (forehead, upper lip, chin, around the mouth) or, conversely, dry out the mouth and eyes. The person may then blink excessively or half-close their eyes, lick or bite their lips, swallow frequently. Biting one’s lips in response to an awkward question, or pressing them together, is somewhat akin to holding back words in one’s mouth: one prefers not to answer.
These emotions sometimes pass very quickly. Researcher Paul Ekman referred to these fleeting expressions as "micro-expressions," based on work conducted in 1966 by Haggard and Isaacs, who identified expressions in couples therapy films that were so brief they required slow motion to be seen (some lasted 1/15th or 1/25th of a second). More than 99% of people cannot identify them, including psychologists and police officers, but training can help learn to recognize them in real time. Also watch for asymmetrical expressions, which engage only one half of the face: a false smile, or an "I love you" spoken with clenched teeth.
When someone lies, changes in voice and pauses are among the most telling clues: the voice becomes higher-pitched, quivers, or suddenly increases in volume, and the speech is filled with hesitations. For some body language experts, these hesitations are even a good indicator, while words that come out effortlessly are more likely to be true.
The mechanism is primarily physical. Under stress, the muscles of the vocal cords tense up (an instinctive reaction), resulting in a higher and sometimes trembling voice. The liar then clears their throat to relieve this tension, a reflex that can also signal dishonesty. The volume can suddenly spike: the person raises their voice because they feel defensive.
The way of speaking reveals other clues.
Expressions of sincerity: "to be honest," "honestly," "here's the truth"... These sometimes indicate that one is trying too hard to convince you.Filler words: "that is," "kind of," "mmm." Research conducted at the University of Michigan has shown that speech frequently interrupted by these words is a common indicator of deception, as they allow time to think of what to say next.Construction time: a person who takes a long time to assemble their sentences on a seemingly simple question may be fabricating them.
To exploit these auditory clues, listen to the person talk about trivial subjects, then about the sensitive topic, and compare the pitch of their voice, the volume, the number of pauses, and the recurrence of the same phrases. A clear discrepancy between the two moments is worth more than an isolated hesitation, which may simply stem from nervousness.
No, body language does not really prove that a person is lying: no isolated sign allows us to assert that there is deception. Researchers like Ekman, Frank, DePaulo, Burgoon, and Vrij have reiterated that there is no single behavior that betrays deceit.
The debate remains lively, especially in the field of mental health, regarding the signals that could accurately identify a lie. Eye contact is the best example. It is commonly believed that liars avoid eye contact, and many indeed struggle to maintain it... however, in a study from the University of Michigan involving 120 videos of court cases, 70% of liars looked directly into the eyes of the person they were deceiving. The question is still unresolved.
The real issue is nervousness. A person may be tense or uncomfortable for many reasons, and what their body shows are indicators of stress, anxiety, aversion, or tension, not lies. Hence the more useful idea of using these signs as a "problem detector": in the face of visible discomfort, the right question is not "are they lying?" but "what is bothering them?". Contempt is also not a sign of deceit, as it can be observed in sincere individuals questioned by someone they deem incompetent or of lower status.
Finally, our detection abilities remain modest. On average, people only identify a lie in 49 to 53% of cases, just barely more than half the time, and the polygraph (which measures tension and pulse at the fingers) relies on physiological reactions whose validity is questionable. So keep a simple rule: never condemn someone based on a single gesture, at the risk of ruining a friendship or a romantic relationship for nothing.
To know if your partner is lying to you, instinct is a good starting point, but it is not enough: it needs to be complemented by questions, observation of body language, and listening to how they speak. Instinct easily spots the most blatant lies, but much less so the others, and you don’t always trust it when it whispers that your partner is cheating on you.
This distrust of one’s own instinct has an explanation. Our relationship with the person influences our judgment, and we often refuse to believe that they are lying to us, especially when it comes to our loved ones. However, intuition sometimes picks up on what’s wrong in body language even before we can explain it (that vague feeling that a polite, kind person who says the right things still doesn’t convince you).
To verify a doubt, proceed step by step:
Start with baseline behavior: remember how the person looks, speaks, and moves when they are sincere or recalling a memory.Ask questions, first neutral, then about the point that worries you, and observe the response: hesitation, gaze shifting elsewhere, gestures that come after the words.Listen to the voice and pauses: changes in pitch, rising volume, phrases like "honestly."Look for discrepancies between what is said and what the body expresses, rather than relying on an isolated sign.
Certain situations make signs more visible: when the liar knows you are paying attention to these details, when they are not used to lying, when they already have a reputation for being a liar (they then have to double their efforts to be believed), or when the stakes and consequences are high. The good news is that training pays off: studies indicate that trained individuals achieve 90% accuracy in detecting signs of lying. In summary, establish a baseline, monitor the body, face, voice, and words, then keep a cool head... observing is not suspecting, and the goal remains to understand what is happening, not to conduct a trial in every conversation.
Author Audrey on 23 February 2023
Education and Training : Association and Organization
Author Audrey on 09 July 2024
Education and Training : Training