A body language and behaviour expert has shared the telltale signs that someone is likely lying, including one subtle movement that can be a real giveaway. Speaking to host Steven Bartlett on a previous episode of his show, Diary Of A CEO, expert Vanessa Van Edwards told viewers of all the signals to look out for when someone is speaking and you think they may not be telling the truth.
Vanessa created Science of People, a human behaviour research lab and educational platform. She also wrote the bestselling books Captivate: The Science of Succeeding with People and Cues: Master the Secret Language of Charismatic Communication. She has taught courses through Harvard University's Division of Continuing Education, too.
Disgust as a key sign of dishonesty
During the episode, Vanessa explained that disgust is a significant, cross-cultural facial expression that often surfaces when someone is being dishonest. She claims that this happens because people who lie frequently experience internal discomfort or feel "dirty" about their deceit, which manifests physically, even if they are unaware of it.
According to Vanessa, this expression involves specific involuntary muscle movements. The person will typically crinkle their nose upward and flash the whites of their upper teeth. This reaction is often accompanied by a sniff, which serves as a "disgust activator" related to the body's natural instinct to close off the nasal cavities to avoid inhaling something unpleasant.
"The biggest one for liars, the research finds, is disgust," she said. "Disgust is an expression that people make without realising it and this is across cultures.
"When we don't like something, or we smell something bad, we crinkle our nose up, and we flash the upper whites of our teeth. You'll notice that liars typically feel dirty when they lie, so oftentimes they'll show disgust with themselves for lying."
Practical cues and other warning signs
In practical application, she says these cues are useful for identifying when someone might be uncomfortable with a specific topic, proposal, or plan. By watching for these physical signs—such as nasal wing dilation or scrunching—during a conversation, she suggests you can identify when someone is not truly aligned with what is being said, signalling that it is time to "double click" and investigate further.
Vanessa also stressed to viewers that detecting lies is difficult, as the average person only achieves about 54% accuracy—essentially no better than flipping a coin. She emphasises that there is no single "Pinocchio's nose" sign for deception, but rather specific statistical cues that warrant further investigation.
Besides the 'disgust' expression, Vanessa shared three other possible telltale signs to watch out for. First, she said to be wary of people using an upward, questioning tone when making a statement or sharing a fact, as this may indicate that the speaker may lack confidence or is hiding something.
Secondly, she mentioned that a sudden loss of volume or breath during a conversation often signals anxiety, which frequently occurs when people are being dishonest about a specific topic. Thirdly, she spoke about nonverbal incongruence. She said a major indicator is a mismatch between verbal and body language, such as saying "yes" while shaking one's head "no."
