If you’ve been following Dr. Ekman’s work, you’ll know there is no single, definitive sign that we can count on to let us know with absolute certainty that someone is lying. Instead, deception detection is a more complex and nuanced process, gathering possible clues to deceit, and investigating further. This often involves observing one’s behavior to establish a “baseline”, and collecting information about any deviation from this norm, in the form of “hot spots”. 

When observing someone, body language is one of five channels of information to pay attention to, along with facial expressions, voice, verbal style and verbal content. There are many pseudoscience claims and myths about how to tell if someone is lying based on their body language. Here, we will distinguish what science tells us about nonverbal communication and deception. 

Gestures and deception

Dr. Ekman studied three types of gestures : illustrators, manipulators and emblems.  

• Illustrator gestures occur during speech as it is spoken. They are used to provide emphasis, to make an action the speech is describing, to trace the flow of thought, to show spatial relationships, or to draw a picture in the air.
• Manipulator gestures are movements in which one body part “manipulates” or interacts with another part of the body (i.e. one part of the body grooms, massages, rubs, holds, pinches, picks, scratches, etc. another body part).
• Emblem gestures are movements that have very precise meanings known within an ethnic, cultural, or sub-cultural group. Emblems are used as deliberately and consciously as spoken words, and are unique in that they can be used in conjunction with or in place of words.

Of these three types of gestures, there are many myths about manipulators in particular. However, the only type of gesture that can reliably provide clues to deception are emblems. 

Manipulator gesture myths

Lie catchers often mistakenly judge a truthful person to be lying because they show many manipulators. An increase in manipulator activity is not a reliable sign of deceit, but many people think it is. People observing manipulators are subject to the two biggest errors in detecting lies: the Brokaw Hazard (failing to account for individual differences in behavior) and the Othello Error (failing to understand that emotions don’t tell you their cause). 

Accounting for the Brokaw Hazard, there is a great deal of individual difference in the type and frequency of manipulators a person shows. So, simply observing someone to be using “a lot” of manipulators does not in itself reveal anything about that person’s emotional state or whether they may be lying. For some people, using many manipulators is a part of their baseline behavior. 

Considering the Othello Error, while it is true that manipulators often increase when someone is feeling discomfort, you can not know simply by observing their behavior (an increase in manipulators), what the cause of that discomfort could be. There could be many possible reasons for feeling uncomfortable, apart from lying. 

Furthermore, manipulators are unreliable as signs of deceit because they may indicate opposite states- discomfort or relaxation. In addition to increasing in a state of discomfort, manipulators may also increase when someone is very at ease and “letting their hair down”. 

Also, considering that an increase in manipulators has entered the general folklore as something that betrays deceit, a motivated liar will likely be aware of this and consciously inhibit their manipulators. 

Emblematic slips are a reliable clue to deceit

Sometimes, when people believe they cannot or should not reveal something that they are thinking, emblematic slips occur, revealing information the person wants to conceal. Often the person who shows the emblematic slip is unaware of doing so. In emblematic slips, only a fragment of the full emblem may be shown. Often it is outside of the presentation position, the space right in front of the person’s chest or face.

Dr. Ekman has studied three common examples of emblematic slips:

1. The most common is a fragment of the shrug gesture. In its full expression, a shrug can include the raising of the shoulders, the rotating of the palms upwards, and movement in the forehead and lips. We have observed some fragment of the shrug (a slight rotation of one hand or slight raising of just one shoulder) in conversations that suggest a contradiction to what the person is actually saying. It typically directly contradicts the confidence, certainty or affirmation that occurs in the speaker’s words or behavior.
2. Another common emblematic slip is a very tiny fragment of the head shake ‘no’ or head nod ‘yes’, directly contradicting the words that are spoken.
3. One more is the display of giving someone “the finger” outside of the presentation position. This could be in the form of placing one’s hand on one’s leg with the middle finger extended, or resting or scratching the side of one’s face with just the middle finger. We have found this emblematic slip can sometimes reveal unconsciously harbored feelings of distaste or anger at someone. 

Along with micro expressions, emblematic slips have proven to be some of the most valuable body language signals that a person is lying. However, remember that this form of nonverbal communication does not always occur during deception. As with other signs of lying we have discovered, its absence means nothing, though its presence can be revealing.

Keep learning and start practicing!

To empower yourself to detect lies, you can learn more about nonverbal communication, the science of deception, and train to detect micro expressions.