How to Tell If Someone Is Lying

How to Tell If Someone Is Lying

Lying and deception
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Lying and deception are common human behaviors. Until relatively recently there has been little actual research into just how often people lie. Some surveys have suggested that as many as 96 percent of people admit to lying at least sometimes. One national study of 1,000 U.S. adults found that sixty percent of respondents claimed that they did not lie at all. Instead, the researchers found that about half of all lies were told by just 5 percent of all the subjects. The study suggests that while prevalence rates may vary, there likely exists a small group of very prolific liars.

The reality is that most people lie from time to time. Some of these lies are little white lies intended to protect someone else’s feelings (“No, that shirt does not make you look fat!”). In other cases, these lies can be much more serious (like lying on a resume) or even sinister (covering up a crime).

People Are Surprisingly Bad at Spotting Lies

People also like to believe that they are pretty good at detecting lies and folk wisdom suggests a wide variety of ways to root out dishonesty. Some of the most common: Liars tend to fidget and squirm. They won’t look you in the eye. They have shifty eyes when they are telling a lie. Research suggests that most of these notions are simply old wives tales.

While there are plenty of tips out there for uncovering dishonesty, research has shown that people are surprisingly bad at detecting lies. A 2006 study by Bond and DePaulo found that people were only able to accurately detect lying 54 percent of the time in a lab setting – hardly impressive considering a 50 percent hit rate purely by chance alone. Other studies have shown that even trained investigators are remarkably poor at telling if someone is lying or telling the truth.

Clearly, behavioral differences between honest and lying individuals are difficult to discriminate and measure. Researchers have attempted to uncover different ways to detecting lies. While there may not be a simple, tell-tale sign that someone is dishonest (like Pinocchio’s nose), researchers have found a few helpful indicators. Continue reading to learn more about what body language can (and cannot) tell you, how to actively root out lies, and why you should trust your instincts.

Body Language

Lying body language
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When it comes to detecting lies, people often focus on body language “tells,” or subtle physical and behavioral signs that reveal deception. Some of the standard suggestions are that shifty eyes, constant fidgeting, and avoiding eye contact are sure-fire signs that the speaker is not telling the truth.

While body language cues can offer clues to deceptions, research suggests that many of the most expected behaviors are not strongly associated with lying. Researcher Howard Ehrlichman, a psychologist who has been studying eye movements since the 1970s, has found that eye movements do not signify lying at all. In fact, he suggests that shifting eyes mean that a person is thinking, or more precisely, that he or she is accessing their long-term memory.

Other studies have shown that while individual signals and behaviors are useful indicators of deception, some of the ones most often linked to lying (such as eye movements) are among the worst predictors. So while body language can be a useful tool in the detection of lies, the key is to understand which signals to pay attention to.

So Which Signals Are Linked to Lying?

Psychologists have also utilized research of body language and deception to help members of law enforcement distinguish between the truth and lies. Researchers at UCLA conducted studies on the subject in addition to analyzing 60 studies on deception in order to develop recommendations and training for law enforcement. The results of their research were published in the April issue of the American Journal of Forensic Psychiatry.

A few of the potential red flags the researchers identified that might indicate that people are deceptive include:

  • Being vague; offering few details
  • Repeating questions before answering them
  • Speaking in sentence fragments
  • Failing to provide specific details when a story is challenged
  • Grooming behaviors such as playing with hair or pressing fingers to lips

Lead researcher R. Edward Geiselman suggests that while detecting deception is never easy, quality training can improve a person's ability to detect lies.

"Without training, many people think they can detect deception, but their perceptions are unrelated to their actual ability. Quick, inadequate training sessions lead people to over-analyze and to do worse than if they go with their gut reactions."

Body Language Cues Are Often Weak

Research has also shown that people do tend to pay attention to many of the correct behavioral cues associated with deception. A 2001 meta-analysis by researchers Hartwig and Bond found that while people do rely on valid cues for detecting lies, the problem might lie with the weakness of these cues as deception indicators in the first place.

Some of the most accurate deception cues that people do pay attention to including:

  • Being vague: If the speaker seems to intentionally leave out important details, it might be because they are lying.
  • Vocal uncertainty: If the person seems unsure or insecure, they are more likely to be perceived as lying.
  • Indifference: Shrugging, lack of expression, and a bored posture can be signs of lying since the person is trying avoid conveying emotions and possible tells.
  • Overthinking: If the individual seems to be thinking too hard to fill in the details of the story, it might be because they are deceiving you.

The lesson here is that while body language may be helpful, it is important to pay attention to the right signals. Experts suggest that relying too heavily on such signals may impair the ability to detect lies. Next, learn more about a more active approach to figuring out if someone is telling the truth.

Ask Them to Tell Their Story in Reverse

How to detect lies
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Lie detection is often seen as a passive process. People often assume that they can just observe the potential liar’s body language and facial expressions to spot obvious “tells.” While research has shown that this is a pretty bad way to detect lies, taking a more active approach to uncovering lies can yield better results.​​

Increasing the Mental Load Makes Lying More Difficult

Research suggests that asking people to report their stories in reverse order rather than chronological order can increase the accuracy of lie detection. The researchers suggest that the verbal and non-verbal cues that distinguish between lying and truth-telling become more apparent as cognitive load increases. In other words, lying is more mentally taxing than telling the truth. If you add even more cognitive complexity, behavioral cues may become more apparent.

Not only is telling a lie more cognitively demanding, but liars typically exert much more mental energy toward monitoring their behaviors and evaluating the responses of others. They are concerned with their credibility and ensuring that other people believe their stories. All this takes a considerable amount of effort, so if you throw in a difficult task (like relating their story in reverse order), cracks in the story and behavior tells might become easier to spot.

Relating a Story in Reverse Leads to Better Lie Detection

In one study, 80 mock suspects either told the truth or lied about a staged event. Some of the individuals were asked to report their stories in reverse order while other simply told their stories in chronological order. The researchers found that the reverse order interviews revealed more behavioral clues to deception.

In a second experiment, 55 police officers watched taped interviews from the first experiment and were asked to determine who was lying and who was not. The investigation revealed that law enforcement officers were better at detecting lies in the reverse order interviews than they were in the chronological interviews.

This sort of active approach to lie detection can be particularly useful in law enforcement situations, but what about the day-to-day? Next up, learn more about why trusting your immediate associations might be your best bet.

Trust Your Instincts

Trust your instincts
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According to the results of a 2014 study, your immediate gut reactions might be more accurate than any conscious lie detection you might attempt. In the study, researchers had 72 participants watch videos of interviews with mock crime suspects. Some of these suspects had stolen a $100 bill from off a bookshelf while others had not, yet all of the suspects were told to tell the interviewer that they had not taken the money.

Similar to previous studies, the participants were pretty bad at detecting lies, only accurately identifying the liars 43 percent of the time and the truth-tellers 48 percent of the time.

But the researchers also utilized implicit behavioral reaction time tests to assess the participants more automatic and unconscious responses to the suspects. What they discovered was that the subjects were more likely to unconsciously associate words like "dishonest" and "deceitful" with the suspects that were actually lying. They were also more likely to implicitly associate words like "valid" and "honest" with the truth-tellers.

The results suggest that people may have an unconscious, intuitive idea about whether someone is lying. So if our gut reactions might be more accurate, why are people not better at identifying dishonesty?

Researcher Leanne ten Brinke suggests that our conscious responses might interfere with our automatic associations. Instead of relying on our instincts, we focus on the stereotypical behaviors that we often associate with lying such as fidgeting and lack of eye contact. By overemphasizing behaviors that unreliably predict deceptions, we hurt our chances of distinguishing between truth and lies.

Final Thoughts

There are a lot of articles out there on how to detect lies. Many of them rattle off a laundry list of the old-wives tales about lying behaviors even though the existing research has shown that most of these stereotypical behaviors do not really reveal dishonesty.

What’s the best way to spot a liar? The reality is that there is no universal, sure-fire sign that someone is lying. All of the signs, behaviors, and indicators that researchers have linked to lying are simply clues that might reveal whether a person is being forthright.

So the next time you are trying to gauge the veracity of an individual's story, stop looking at the clichéd “lying signs” and learn how to spot more subtle behaviors that might be linked to deception. When necessary, take a more active approach by adding pressure and make telling the lie more mentally taxing by asking the speaker to relate the story in reverse order.

Finally, and perhaps most importantly, trust your instincts. You might have a great intuitive sense honesty versus dishonesty, you just need to learn to heed those gut feelings.


Bond, C.F., & DePaulo, B.M. (2006). Individual differences in judging deception: Accuracy and bias. Psychological Bulletin, 134(4), 477-492.

Brinke, L.T., Stimson, D. S., Carney, D.R. (2014). Some evidence for unconscious lie detection. Psychological Science, 25(5), 1098-1105. 10.1177/0956797614524421.

Ehrlichman, H., & Micic, D. (2012). Why do people move their eyes when they think? Current Directions in Psychological Science, 21(2), 96-100. doi: 10.1177/0963721412436810.

Geiselman, R.E., Elmgren, S., Green, C., & Rystad, I. (2011).  Training laypersons to detect deception in oral narratives and exchanges.  American Journal of Forensic Psychology, 32, 1-22.

Hartwig, M., & Bond, C.F. (2001). Why do lie-catchers fail? A lens model meta-analysis of human lie judgments. Psychological Bulletin, 137(4), 643-659.

Serota, K.B., Levine, T.R., & Boster, F. (2009). The prevalence of lying in America: Three studies of self-reported lies. Human Communication Research, 36(1), 2-25. DOI: 10.1111/j.1468-2958.2009.01366.x.

Vrij, A., Mann, S.A., Fisher, R.P., Leal, S., Milne, R., & Bull, R. (2008). Increasing cognitive load to facilitate lie detection: The benefit of recalling an event in reverse order. Law and Human Behavior, 32(3), 253-265.

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