Signs of deception: How to spot lies

Have you ever had the feeling in a conversation that what is being said could be a lie? Wouldn’t it be cool to know some deception body language sign that could tell you if the other person is dishonest to you?

Unfortunately, no such single sign exists that could tell you with certainty whether a statement is true or false. Lie detection is a complex behavioral analysis that never trusts a single behavior that has been torn out of context.

But there are several behaviors that occur more often when someone is nervous, feels unwell, or wants to hide something from you. Depending on whether these behaviors deviate from the person’s usual behavior and what their context of occurrence is, they may indicate a lie.

Here I give you an overview of some of these deception signs.

If you see several of them appearing in clusters at short intervals in succession (we’re talking about the range of seconds), you should hear the alarm bells ring and ask yourself if what has just been said is true.

Why are we so bad at detecting lies?

Scientific research suggests that, on average, an untrained person is only marginally better off than sheer coincidence in correctly judging whether something is a lie or truth (Bond, Jr. & DePaulo 2006).

So, if you threw a coin: Heads – someone lied to you, tails – he didn’t, you’d be right almost as often when you throw the coin as when you read the person’s behavior.

You may wonder why we are so bad at detecting lies.

Well, first of all, the liar has an unfair advantage: he knows he is lying while you do not.

In fact, we even assume by default that other people tell us the truth.

Thus, unless you find logical contradictions in what has been said, or your gut feeling tells you that something is wrong, you assume that other people are speaking truthfully.

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

Besides, we falsely believe that we can recognize lies very well, and we rely heavily on that.

We are certain that we will notice every lie presented to us, so we drop our safety precautions and miss many critical alerts.

As we speak of warning signs, some false myths about lying and its visible behavioral patterns persist, misleading us in the search for truth.

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

Typical signs of deception

Just to repeat that: There is not a single accurate lie indicator that could tell you for sure if someone is lying to you.

But multiple behaviors occur more often when people are lying. Here are some typical signs of deception.


micro expressions
Micro-expressions. © master1305 | Envato Elements

Micro-expressions are rapid facial expressions (read our Micro-Expression Guide) that can only be seen on the face for a small fraction of a second before disappearing.

Because of their fast speed, it’s well known that micro-expressions are hard to spot. However, you can train your ability to recognize micro-expressions on the faces of others.

Micro-expressions indicate a person’s hidden, often subconscious emotions (see the basic emotions and their facial expressions).
Therefore, micro-expressions are very suitable for detecting deceptions.

For example, imagine that a particular topic makes a person sad, but that person hides their grief from you. In that case, you’ll probably see the micro-expression of sadness flashing over 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 wearer about a particular topic.

If you perceive the micro-expressions of your counterpart in time and know how to interpret them correctly, you have valuable additional information. On this basis, you can decide what further questions you can ask to understand the underlying problem.

Micro-expressions can also be a specific sign of deception if the emotion seen in the micro-mimic doesn’t match 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 incongruity between the micro-expressions and the content of the conversation may indicate a lie.

You will see an example of this later in the video talk at the end of this blog post.

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Linear time sequence

Lying is cognitively very demanding. The liar not only has to remember real events but has to construct a parallel story (or reality, depending on how big the lies are) and keep an eye on both at the same time.

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

Liars often tell their story linearly from beginning to end. Not only do they have to create and manipulate the details in the story spontaneously, but they also have to avoid contradictions.

Telling events in a nonlinear manner would add an extra dimension of complexity to their cognitive processing since they can not rely on real memories. Therefore, it is difficult for a liar to tell his invented story nonlinearly without falling into contradictions.

Forensic interviews often take advantage of this fact when the interviewee is asked, for example, to describe the events backward.

Protective reflexes

Often people show during a lie so-called protective reflexes in their body language. These reflexes are involuntary movements that are subconscious. As the name implies, they aim to protect the body.

An example of a protective body reflex could be to cover or touch sensitive body areas such as the neck or face.

Especially neck touches are often found during lying.

It can also happen occasionally that the liar moves objects or his body parts between himself and the interviewer (like a privacy screen) to protect his body.

deception signs - covering lips
Covering mouth. © stokkete | Envato Elements

For example, sometimes they hide their mouths behind objects like a book, a pen, or their fingers.

In the example on the right, you can see a woman placing a finger vertically on her lips.

Ironically, it looks like she wants to remember keeping her lips sealed.

This behavior, along with other signs, may be an indication that she does not want to tell the full story or intentionally withholds information.

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

Verbal repetitions

When they lie, people often repeat individual words, phrases or sentences, which sounds like a broken record.

Pay attention to 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, he does not have to repeat a phrase to convince himself or others of the correctness of their words.

In fact, it is no secret that you are more likely to believe something you have heard many times, even if you do not know if it is true or false.

This is the power of repetition.

With this technique, a liar can manipulate your beliefs, whether he is aware of it or not.

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

Quiz: Lie detection myths

There are many myths about deception and lies detection. Can you distinguish facts and fiction?

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Eye contact

When asked about the prototypical behavioral trait of a lie, many people respond that liars avoid eye contact.

However, eye contact itself is not a reliable indicator of lies. Some people even hold more eye contact when lying than they usually do.

Especially experienced liars can sometimes literally stare at you because they want to appear honest (yes, they have heard the myth that liars look away, too 😉) and they are curious about whether you believe their lie.

Can you tell by eye contact if someone is lying?

Some people naturally have less eye contact than others, which may be due to specific characteristics of their personality, such as introversion, or to clinical disorders such as autism.

The amount of eye contact also varies between different cultures. Some cultures consider prolonged eye contact as offensive.

Besides, people’s eye contact varies in different situations, depending on the person’s current physical and mental state (e.g., fatigue).

Various interpersonal relationships between the person and any other persons present in the room (e.g., interest) may alter eye contact.

And, most importantly, people can consciously control or change their eye contact.

As you can see, the interpretation of eye contact regarding deception is quite complicated, as you have to consider many additional factors.

Too many details

The liar wants his invented story to sound as real and as natural as possible.

Because you would rather buy the lie, if the image in your imagination is alive, the liar decorates his story with many unimportant details. In this way, he tries to build trust and and make a cooperative impression on you.

Often, these details also contain some truths that the liars can resort to when their story needs proof. A liar usually gives you much more information than necessary.

In contrast, people who tell the truth do not need to overload their story with unnecessary detail.

Statements to convince you

The liar is actively trying to convince you what a good person, employee, citizen, friend, parent, etc. he is. You often hear statements like:


  • would never do something like this
  • always had a good reputation, why should I risk it?
  • love my wife I would never do her any harm
  • 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 such a thing about you
  • why should I do something like this?

Note that these statements do not say, “I did not do it,” but try to convince you of the person’s moral righteousness.

The liar aims to make you believe that they are on your side and that you should see them in a good light.

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Physiological changes

During the 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 tissue. As a result, some people (especially small children) can blush if they are lying.

Other physiological changes include faster breathing and increasing the pulse rate. These changes can be very subtle, but sometimes they are visible from the outside.

Polygraphs, which are technical measuring instruments that are (controversially) used for the detection of lies, can register such changes.

Lie tests using polygraphs

However, one should be extremely careful in interpreting their results as they can only point to physiological stress reactions.

In other words, they do not directly detect lies, but instead, provide clues as to whether someone who is confronted with specific questions experiences physical stress reactions.

Lie tests with polygraphs can lead to false results caused by clinical conditions (e.g. flat affect, psychopathic personality disorder), previous training (how to pass a lie detection test), or by emotional arousal independent of lies.

How to interpret deception signs

Caution Note

None of these signs prove that someone is lying. Likewise, the absence of these signs does not show that someone is telling the truth.

All of these signs usually appear when someone is under stress, anxiety or insecurity. Besides, this list is not exclusive: there are more signs than the ones shown here.


In different contexts, the same behavioral sign can mean completely different things or mean nothing at all.

Therefore, a single behavioral sign 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.


These signs are very timely to the lie (in milliseconds to seconds). So they can appear while you’re still talking, but the liar is already thinking about telling a lie. Or during his lie or shortly thereafter.

If you notice the behavior at another time during the conversation, such as when you talk about the weather, it is most likely not a sign of a lie.

Behavioral baseline

It is crucial to first determine the so-called behavioral baseline of a person before interpreting their behavior in extraordinary situations.

In other words, it is important to consider what kind of behavior a person shows under typical conditions. Otherwise, one could misunderstand behavior as a lie, which is typically more common in this person.

Videos on lie detection

Here you can find some interesting videos on lie detection.

I will keep updating this list in the future, so be sure to check back every once in a while.

You could start by watching the famous TED talk “How to spot a liar” by certified fraud examiner Pamela Meyer, in which you can also find other signs of deception.

At the end of the talk she shows a stunning video example of incongruent emotional reactions in a lying killer compared to congruent emotions in a grieving parent.

Check out also this interesting 40 minute video lecture of former CIA officer, Susan Carnicero, who is also author of “Spy the Lie” on Youtube: Former CIA Officer Will Teach You How to Spot a Lie.

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

All the best,

Signs of deception: How to spot lies

+Scientific sourcesMedia attributionsLegal disclaimer

Here you can find more information, such as the scientific studies to which I refer, and the attribution lines of the media. Please also read the legal information. Just click on the tabs above this text.

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

Featured image: Man with a nose like Pinocchio. © Believeinme |

Image Micro-expressions: Set of young woman’s portraits with different emotions. © master1305 | Envato Elements

Image Covering mouth: Pensive young woman. © stokkete | Envato Elements

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