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Adaptors, Facial Expressions and NOT-Face or how to spot a Liar in Negotiations

Just about everyone you know tells low-stakes lies and let’s be honest, each one of us sometimes falls for a little white lie. Small lies are part of everyday life: several times a day we tell the untruth. Not every lie is morally reprehensible from a psychological point of view. We often want to spare somebody’s feelings or avoid disputes and conflicts. It is therefore a fact that our social interaction cannot work without lies. However, there are situations in which lies do not serve the social coexistence, but lead to the individual disadvantage of the deceived party.

Especially in negotiations, lies and deceptions are constant companions. Everyone wants to bring out the best for his organisation. The means of deception then appears to be a helpful way to get there. No matter whether mentioning wrong numbers, false pretences or simply the withholding of information: the list of possibilities is endless. So wouldn’t it be very helpful to know how to detect a liar in negotiations?

The signs that someone is lying aren’t always easy to decipher. But there are clear indications to spot the liar or at least to not let yourself be manipulated by deceptions. Here are a five techniques to determine if someone is telling the truth or not.

  1. Spotting the lie

There is one decisive circumstance that helps to detect the liar: lying is hard work. It is quite exhausting for the brain, because lies need more cognitive resources and our brain needs more energy. A liar does not only need convincing arguments and an appropriate body language, but also matching facial expressions and emotions. This induces stress in the liar’s body. Even experienced liars such as professional criminals and poker players (especially the last group is extremely trained in recognizing non-verbal incongruence) do not have the brain power and know-how to manage it all without letting something go – without ‘leaking’. The best way to catch these leaks is to look for differences and discrepancies in your negotiating partner’s behavior as well as significant stress signals.

  1. Evidence for the detection of lies

In order to provide evidence for someone telling lies, you should focus on looking for discrepancies in a person’s behavior by paying attention on two levels: WHAT my counterpart says and HOW it says it:


Words are quite easy to analyze: Mistakes and contradictions in content are indicators of inconsistencies.


Your own voice can also quickly become a pitfall. The problem: We only hear and perceive our voice when we say something, and then it can already be too late. The deviation from the normal pitch of the voice is therefore usually a good indication for the emotional excitement of your negotiating partner. A remarkably low voice pitch, but also sudden, louder or faster speaking can be important indications for stress symptoms and thus for the fact that our counterpart is insecure – perhaps because he or she is lying. Finding these clues – and using them for one’s own purposes – is crucial for successful negotiations, especially in telephone negotiations.


Adaptors are so-called calming gestures. The intensified pressing of lips, hands or fingers, the increase of touches in the face, shuffling feet or also nervous turning of a pen: These are all nonverbal signals in order to control the arising stress.

And as the most important indication: Facial expressions

  1. Microexpressions: When the face speaks volumes

You should pay particular attention to the so-called microexpressions. Microexpressions describe expressions on our face that we cannot consciously control. Because our face usually betrays more than we want it to. The so-called “Facial Action Coding System” is not an integral part of the FBI’s investigation techniques (FACS, “Face Movement Coding System”) for nothing. According to the scientist Paul Ekman, there are seven basic emotions that are constant across cultures. A distinction is made between anger, grief, fear, contempt, joy, surprise and disgust. In negotiations of any kind it is crucial for success to recognize and evaluate these microexpressions. They reflect the emotional state of your counterpart and can disappear after a fraction of a second. For the untrained eye, microexpressions are usually difficult to detect. But they offer exciting clues about what we think and how we feel towards each other. Behind every mimic expression there is a “trigger” that provokes the emotion and gets activated on the basis of a profit or loss expectation regarding a relevant topic. This is exactly the situation that we have in a negotiation. That’s why dealing with the FACS is a crucial part of our professional negotiation training.

  1. If a “Yes” is a “No” – The NOT Face

The so-called “NOT face” is particularly noteworthy at this point: a team led by cognitive researcher Aleix Martinez from the University of Ohio came across the “no face” in 2016. It is the rejection of a statement or situation cast in facial expressions: frowning, compressed lips, a slightly raised chin. Whenever the test persons formulated a sentence with the negative word “not”, they showed the “no face”. This expression is the international mimic for “no”, which works in all languages. It is interesting to note that the participants in the experiments also made the “no face” – if they answered “yes”, but actually meant “no”. The newly discovered NOT Face is another facial expression that indicates if someone is lying – and that across cultures!

For the study, the research team selected special cultural backgrounds with different grammatical origins: English, Spanish and Mandarin. The average frequency of the NOT Face is about 5.68 Hz (approx. 170 milliseconds). This lies within the range of 3 to 8 Hz that we use in language to produce word syllables. It is an indication that facial expressions, in this case the NOT Face, are used as grammatical markers (here for negation). This shows the connection of mimic signals to the development of language.

  1. BUT: You are blind without a baseline

So far, so clear: Even if we remain silent, our body is communicating nonverbally. This is used by professionally trained negotiators to figure out the emotions and movements of the negotiating partner and their underlying motives. They are consciously looking for contradictions, because: People can choose their words with caution, one can keep one’s voice in check with practice and perhaps even put on the poker face – but hardly anyone will manage to keep all verbal and non-verbal channels under control at the same. At some point, an incongruity seeps through somewhere.

So the key to successfully spot a liar is observation. Therefore, keep an eye on the behavior and the non-verbal signals of your counterpart in a “lie-free” state. The better you know the so-called “baseline”, i.e. the respective “normal behaviour”, the easier it will be to perceive incongruities and deviations.

In my bestseller for negotiations, “Das FBI Prinzip“, I explain in detail how you work with micro-expressions in negotiations. In my negotiation trainings, I also show you strategies for sharpening your observation skills, the ability to recognize microexpressions, learning to use the NOT face and exposing lies to your negotiating counterparts.


  • truth:  geralt, Pixabay | CC 0 Public Domain

Thorsten Hofmann, C4 Institute, Quadriga University Berlin

Thorsten Hofmann leads the CfN (Center for Negotiation) at the Quadriga University Berlin’s Institute for Crisis, Change and Conflict Communication C4. He is an internationally certified Negotiation Trainer and advises corporations and organisations in complex negotiation processes.