Decoding Deceptive Body Language | Summary and Q&A

June 18, 2015
Stanford Graduate School of Business
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Decoding Deceptive Body Language

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In this video, the presenters discuss the body language of deception and how to spot liars in various situations such as games, interviews, negotiations, and presentations. They go through the different nonverbal cues of deception, starting from the face, then the hands, and finally the feet. They discuss the importance of eye contact, facial expressions, hand gestures, and the positioning of the palms. Additionally, they reveal that feet can be a significant indicator of honesty or deception, highlighting the importance of how someone stands, the movement of their feet, the direction their feet are pointing, and the concept of ankle locking.

Questions & Answers

Q: What are some behaviors to look for in the eyes to detect deception?

The presenter mentions that the dilation and retraction of pupils can be a strong indicator of someone's excitement or disinterest. When someone is dissimulating or not interested, their eyes may blink frenetically or they may avoid eye contact altogether.

Q: How can facial expressions be used to detect deception?

Facial expressions can be faked, but there are clues to detect in genuine expressions. The presenter suggests that genuine emotions show on the face first, before someone speaks. If the emotion seems to align with their speech, it may indicate deception. Also, genuine expressions tend to last less than a second, so if an expression lasts longer, it is more likely to be fake.

Q: How can tongue movements be a clue for deception?

When under pressure or stress, the tongue may flick phonetically. This can be observed when someone is trying to deceive, and it can manifest as repetitive tongue movements. For example, the presenter mentions a testimony where John Kerry flicked his tongue like a snake eight times in 90 seconds, potentially indicating deception.

Q: What hand gestures can be indicators of deception?

The presenter mentions a few hand gestures that may suggest deception. Covering the mouth can be a subconscious attempt to hide lies. Scratching the nose can be a result of increased adrenaline, creating itchiness in the skin. Rubbing the neck or ear can be a reassuring reflex from childhood. These gestures can indicate nervousness and a desire to self-soothe when lying.

Q: How does the timing of gestures differ between truth and deception?

Normally, when speaking and gesturing simultaneously, the gesture precedes the words. However, when someone is lying, they tend to say the words first and then make the accompanying gesture. This delayed timing can be a cue for deception.

Q: What is the significance of the positioning of palms in detecting deception?

Palms are an important part of our body for connecting with others, and when someone is lying, they may feel uncomfortable exposing their palms. They may put their hands in their pockets, place them facing down, or hide them behind an object like a desk. This positioning is an attempt to create a barrier or distance between themselves and the people they are lying to.

Q: How can feet reveal signs of deception?

According to the presenter, feet movements can be very telling. The way someone stands can indicate their comfort level and confidence. Crossing the legs may signify a closed and defensive position. Shifting weight or rocking back and forth can indicate nervousness. The direction of the feet can demonstrate interest or disinterest, while ankle locking can suggest a person is withholding information.

Q: Why are feet considered important in detecting deception?

Since people often focus on controlling their facial expressions and hand gestures when lying, they tend not to rehearse their feet movements. As a result, feet behaviors can be more spontaneous and involuntary, making them potentially more honest indicators of deception.

Q: How many signs of lying should be observed before concluding deception?

It is recommended to view behaviors in clusters and look for at least three signs of lying before accusing someone of deception. Gathering multiple nonverbal cues can strengthen the case for detecting lies.

Q: How should this knowledge be applied?

The presenters suggest using this knowledge not only to spot liars in others but also to recognize and manage one's own nonverbal cues. They give examples of situations like the World Series of Poker, tough negotiations, or interviews where this knowledge can be applied to gain an advantage.


Understanding the body language of deception can help in detecting lies in various scenarios. Nonverbal cues such as eye movements, facial expressions, hand gestures, and feet behaviors can reveal important clues. By observing multiple signs and considering the context, one can become better at spotting deception. However, it is essential to apply this knowledge ethically and use it for personal growth as well.

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