How to Spot a Liar

How can you tell when an employee, job applicant or coworker is telling a lie? Learn to spot deception by watching for these seven tell-tale clues that the person you’re talking to is lying.

1. Establish a “truth baseline”

Spotting deception begins with observing a person’s baseline behavior under relaxed or generally stress-free conditions so that you can detect meaningful deviations. 

One of the strategies that experienced interviewers use is to ask a series of simple questions while observing how the person behaves when there is no reason to lie. Then, when the more difficult issues get addressed, the interviewer can stay alert for sudden changes in behavior that may indicate deception around key points.

2. Watch for stress signals

For the vast majority of the individuals you interview or work with, the act of lying triggers a heightened stress response. Blood pressure, heart rate and breathing rates all increase.

To relieve stress and anxiety, liars may use pacifying gestures (rubbing their hands together, bouncing their heels, fidgeting with jewelry, etc.) But our first response to stress (before we ready ourselves to fight or flee) is to freeze. So also pay attention if your usually animated colleague suddenly stops gesturing, has a forced or frozen smile, and locks her ankles.

3. Look at their eyes

The biggest myth around deception is that liars can’t look you in the eyes. In fact, some don’t (especially small children), but polished liars may actually give too much eye contact.

There are two eye signals that are more accurate signs of dishonesty: 1) Pupils dilate when someone is lying, and 2) Blink rates change – slowing down while someone constructs and tells the lie, and then speeding up (sometimes as much as eight times) afterward.

RELATED: Signs Your Employees Are Stealing from You

4. Count to four

Nonverbal cues to all kinds of unconscious giveaways tend to occur in clusters – a group of movements, postures and actions that collectively point to a particular state of mind.

This is crucially true of dishonesty, where one specific cluster of nonverbal signals has been proven statistically to accompany dishonesty. These are: hand touching, face touching, crossed arms, and leaning away. According to research conducted at Northeastern University by David DeSterno, if you see these “Telltale Four” being displayed together, watch out!

5. Notice if they aren’t really answering the question

Because of the mental effort it takes to tell a bald-faced lie (and because it triggers negative emotions), many deceivers prefer to avoid the truth with quasi-denials and selective wording. Notice how the responses below (which may be absolutely valid) never actually answer the questions.

Question: Have you ever used drugs?

Answer: I don’t take drugs.

Question: Did you steal a computer from the supply room?

Answer: Do I look like the kind of person who would steal a computer?

Question: Did you leave your last place of employment on good terms?

Answer: I left to pursue other opportunities.

Question: Did you pad your expense account?

Answer: How can you ask that? I’ve been a loyal employee for over 10 years!

RELATED: What’s the real story behind employee excuses?

6. Listen for vocal stress

The primary paralinguistic (how you say what you say) signal that often indicates lying is a change in someone’s baseline vocal pitch, which usually rises with stress levels as vocal chords constrict.

Under stress, people may also experience an increased need to drink water and to lick or moisten lips, as the autonomic nervous system downloads a rush of adrenaline, causing a dry mouth.

7. Stay alert for “undercover” emotions

Smiles are often used as a polite response and to cover up other emotions, but these faked smiles involve the mouth only. Unless someone is expressing genuine pleasure or happiness, it’s hard to produce a real smile – the kind that crinkles the corners of the eyes and lights up the entire face.

There is another way that real emotions emerge, regardless of the effort to suppress them. When someone conceals any strong emotion, chances are his face will expose that information in a split-second burst called a “micro expression.” Difficult to spot because of it happens so quickly, but that instantaneous flash of anger, dismay, joy, etc. is an indicator of someone’s genuine emotional state.

Please remember that none of these verbal or nonverbal cues are proof of lying. Truthful people can show signs of stress, have a naturally high blink rate, or give round-about answers. And both the liar and truth-teller may exhibit fear — one of being discovered, the other of not being believed. Nevertheless, these signals are strong indicators of heightened anxiety, possible deception, and of “hot spots” — areas that you should investigate further.

Carol Kinsey Goman, Ph.D., is a keynote speaker, leadership communication consultant, body language coach, and author of The Silent Language of Leaders: How Body Language Can Help – or Hurt – How You Lead. You may read the first chapter of her new book, The Truth About Lies in the Workplace: How to Spot Liars and What to Do about Them here. Carol can be reached by email:, phone: 510-526-1727, or through her website:

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