8 Common signs of deception

Did you ever get the feeling in a conversation that what was said might be a lie? If you see several of these deception signs appearing together in clusters, you should ask yourself if what was just said is true.

Scientific research suggests that a reasonable person is on average only marginally better than pure chance in rightly judging whether something is truth or a lie (Bond, Jr. & DePaulo 2006). Thus, if you threw a coin: Heads up – someone just lied to you, tails up – they didn’t, you’d be almost equally often right by tossing the coin as by reading the person’s behavior.

Why are we so bad at spotting lies?

Well, first of all, the liar has an unfair advantage: he knows that he is lying, while you don’t. In fact, we usually assume by default that people are telling the truth. Thus, unless you find some logical inconsistencies in what they said, or your gut-feeling tells you that something’s wrong, you assume other people they are telling the truth.

I’m not upset that you lied to me, I’m upset that from now on I can’t believe you.Friedrich Nietzsche

Furthermore, we falsely believe that we are very good at spotting lies and we rely heavily on this. Thus, we think that we would notice any lie presented to us, so we let our safeguards down and miss many critical warning signs. Speaking of warning signs, some persistent misconceptions about lying and signs of deception are out there, which mislead us in our quest for truth.

And, last but not least, we sometimes just don’t want to hear the truth, no matter how hard it knocks on our doors, don’t we?

Common signs of deception

Unfortunately, there is not a single accurate behavioral sign of fraud that could tell you with 100% certainty about whether someone lies to you. But several behaviors occur more frequently when people lie. Here you can find some common signs of deception.

Micro-expressions. © master1305 | Envato Elements


Micro-expressions are very brief facial expressions (read our micro-expression guide) that can only be seen on the face for a fraction of a second before disappearing again.

Because of their fast speed, micro-expressions are notoriously difficult to spot. However, you can train your ability to recognize micro-expressions on others’ faces.

Micro-expressions indicate hidden, often subconscious, emotions of a person (see facial expressions of the seven primary emotions). Therefore, micro-expressions are very well suited to uncover deception.

For example, imagine that a particular topic makes a person sad, but that person hides their grief from you. In this case, you’ll probably see the micro-expression of sadness flashing across that person’s face as you talk about the subject.

At the same time, the person does not even have to be aware of their sadness. Thus, micro-expressions reveal hidden emotional aspects of their carrier concerning a particular topic.

If you notice your counterpart’s micro-expressions in time and know how to interpret them correctly, you have valuable additional information. Based on this, you can decide to ask further questions to understand the underlying problem.

Micro-expressions can also be a specific sign of deception if the emotion seen in the micro-mimic is not matching the emotional content of the conversation.

For example, when the person is talking about a sad subject while repeatedly showing the micro-expression of joy. In such a case, the observed incongruence between the micro-expressions and the content of the conversation may indicate deception.

Linear time series

Lying is cognitively very demanding. The liar not only has to remember real events but has to construct a parallel story or reality and keep both in mind at the same time.

If you tell the truth, you do not have to remember anything.Mark Twain

Therefore, liars often linearly tell their story from beginning to end. Not only do they have to fabricate and manipulate the details in their story spontaneously, but they also have to circumvent contradictions.

To narrate the events in a non-linear way would add an extra dimension of complexity to their cognitive processing since they cannot rely on real memories. Thus, it is difficult for a liar to tell his fabricated story nonlinearly without running into contradictions.

Forensic interviews often make use of this circumstance, for example, when the interviewee is asked to describe the events backward.

Protective reflexes

Often people show so-called protective reflexes in their body language during a lie. These reflexes are involuntary movements that happen subconsciously. As the name suggests, they aim at protecting the body.

A protective body reflex could be covering or touching of the sensitive body areas, such as the neck or the face. Especially neck touching is quite frequent in deception. It may also involve the liar placing objects or their body parts between themselves and the interviewer.

Covering mouth. © stokkete | Envato Elements

For example, sometimes they hide their mouths by using objects such as a book, a pen or their fingers. In the example shown on the right site, you can see a woman placing a finger vertically on her lips. Ironically, it looks as if she wanted to remind herself to keep her lips sealed.

Together with other signs, this may be an indication that she does not want to tell the whole story or is deliberately withholding information.

You can find protective body reflexes often when someone lies to protect their interests or self-esteem.

Verbal repetitions

When they lie, people often repeat single words, phrases or sentences over and over again, which sounds like a broken record.

Watch out for such repetitions, as they are a good indicator of lies. The lie often corresponds to the content of the repeated phrase.

When a person tells the truth, they don’t have to repeat a phrase to convince you or themselves of the correctness of their words.

Indeed, it is no secret that you are more likely to believe something, which you repeatedly heard before, even if you don’t know whether it is true or false. So, by using this technique, a liar may manipulate your beliefs, whether he might be aware of this, or not.

Furthermore, sometimes liars repeat what they say to gain more time so they can think about what to say next.

 Quiz: Lie detection myths 

Many myths exist about deception and lie detection. Here you can test your knowledge. Can you tell fact from fiction in lie detection?

Eye contact

When asking people for the prototypical behavioral sign of a lie, many respond that liars avoid eye contact. However, eye contact itself is not a reliable cue for lying; in fact, some people keep more eye contact while lying.

Especially experienced liars may stare at you, because on the one hand they want to appear honest, while at the same time they are very curious if you buy their lie. It is challenging to tell by eye contact whether someone is lying.

Some people naturally hold less eye contact than others, which may be due to specific character traits of their personality, like introversion or shyness, or due to clinical disorders, like autism. The amount of eye contact also varies across different cultures. Some cultures consider prolonged eye contact as insulting.

Also, people’s eye contact varies across different situations, depending on the current physical and mental condition of the person (e.g., fatigue, irritability). Different interpersonal relationships between the person and any other present people in the room (e.g., antipathy or interest) can alter eye contact. And, perhaps most importantly, liars often try to keep more eye contact to appear honest deliberately.

As you can see, interpreting eye contact concerning deception is quite complicated, as you must take many additional factors into account.

Too many details

The liar wants his fabricated story to sound as real and as natural as possible. Because you are more likely to buy the lie, when the image in your imagination is vivid, the liar decorates his story with many unimportant details. This way he attempts to build trust and be likable.

Often these details also contain some truths that the liar can fall back upon if their story needs evidence. A liar usually gives you much more information than necessary.

In contrast, people who tell the truth, don’t need to over-decorate their story with unnecessary details.

Convincing statements

The liar tries to actively convince you what a right person, employee, citizen, boyfriend, parent, etc. they are. You will often hear statements like I…

  • would never do something like this
  • always had a good reputation at work, why should I risk it?
  • love my wife/husband I would never harm her/him
  • am a loving mother/father/grandparent
  • would never steal anything
  • have always been a good employee
  • am an honest person
  • condemn any form of violence
  • would never say this about you
  • why should I do something like this?

Notice that these statements don’t say “I did not do it” but try to convince you of the moral righteousness of the person. The person aims at making you believe that they are on your side and that you should view them in a good light – or otherwise, you are a terrible person.

If several of such statements occur together with other warning signs, this might be an indication that someone is dishonest.

Physiological changes

During deception, the human nervous system enters a state of stress, in which physiological changes occur in the body.

For example, the blood circulation increases and pumps more blood through the body tissues. As a result, some people (especially small children) blush when they lie. Other physiological changes involve faster breathing and an increase in pulse rate. These changes can be very subtle, but sometimes they are recognizable from the outside.

Polygraphs, which are technical measuring devices that are (controversially) employed for lie detection, can register such changes. However, one should be very careful in interpreting their results, as they can merely indicate physiological stress responses. In other words, they do not directly detect lies, but instead provide clues, whether someone is experiencing bodily stress responses faced with specific questions.

Lie tests using polygraphs can yield false results, which can be caused by clinical disorders or abnormalities (e.g., flat affect, psychopathic personality disorder), by preceding training (on how to pass a lie detection test), by emotional arousal independent of lies or just by chance.

About interpreting deception signs

None of these signs prove that someone is lying. Nor, in turn, does the absence of these signs show that someone is telling the truth. All of these signs usually occur when someone is under stress, unwell, anxious or insecure. Also, this list is not exclusive: many more deception signs exist than those featured here.

In different contexts, the same behavioral sign can mean entirely different things, or not mean anything at all. Thus, any single behavioral sign in itself is not reliable enough to accurately recognize and interpret lies. Instead, you should pay close attention to clusters of such warning flags that occur together.

Also, these signs occur in very timely manner around the lie (in matters of milliseconds to seconds). Thus, they may appear while you are talking and the liar is already thinking about telling a lie. Or during the fabrication or shortly after that. If you notice the behavior at another time during the conversation, for instance, while talking about the weather, it’s most likely not a sign of a lie.

It is crucial to first determine a person’s so-called behavioral baseline before interpreting their behavior in extraordinary situations. In other words, to see what kind of behavior a person displays in typical conditions. Otherwise, you could misinterpret a behavior as a lie, which occurs more frequently in this person.

Video talk on lie detection

Below you can watch a famous TED talk “How to spot a liar” by certified fraud examiner Pamela Meyer, in which you can also find a few more signs of deception. At the end of the talk, she shows a perplexing video example of incongruent emotional responses in a lying murderer, as compared to congruent emotions in a grieving parent.



Now you know the basics of lie detection and the common behavioral warning signs that someone might be lying to you.

All the best,


Scientific sources:

Bond Jr, C. F., & DePaulo, B. M. (2006). Accuracy of deception judgments. Personality and social psychology Review10(3), 214-234.

Media sources:

Embedded Video: TED Talk How to spot a liar (Pamela Meyer | TEDGlobal 2011)
Image: Liars. © Alphaspirit | Dreamstime.com

8 Common signs of deception
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8 Common signs of deception
Is the person you are talking to lying to you? When you see some of these signs of deception appearing together, you should critically reconsider whether what was just said might be a lie.
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