How to tell if someone is lying to you

Jane Murphy 8 March 2022

Ever get the feeling someone isn’t being entirely honest with you? Discover how to spot a liar, when to confront them and when to walk away

Would it surprise you to learn that the vast majority of adults—around 75 per cent—tell up to two lies every day? That's according to a recent US study in which 630 participants were asked to keep a “daily deception journal” for three months.

Of course, it's entirely possible that some of these people lied about the amount of lies they told, but let's give them the benefit of the doubt. Indeed, the results tally with previous research which found that, on average, people tell 1.65 lies a day.

What this suggests then is that you've probably told a lie or two in the past 24 hours and chances are you've also been lied to.

Before you start protesting your innocence or confronting loved ones and colleagues, though, it's worth noting that the bulk of these lies fall into the “hardly worth mentioning” category. Think little white lies such as attempting to spare someone's feelings (“I love your new haircut”) or gently tweaking the facts to avoid looking bad (“My train was cancelled” instead of “I overslept and missed my train”).

Even so, there's still a sizeable bunch of prolific liars on the loose. “There is that top one per cent who are telling more than 15 lies per day, day in and day out,” says Professor Timothy Levine, who co-authored the study. At the other end of the scale, meanwhile, are the one per cent of the population who almost never tell a lie.

Why people lie

People tell lies for a variety of reasons, say the US researchers Just over 20 per cent are told in a bid to avoid other people; a further 20 per cent are jokes or pranks; 14 per cent are told in self-protection; 13 per cent are attempts to make a good impression; 11 per cent are told to protect others; and nine per cent are for personal gain.

Still, less than 12 per cent of lies can be categorised as “big lies”—and these are usually the ones that really matter. An example of a big lie, according to the study's authors, would be saying “I love you” without being sincere.

How to spot a liar

So, are there any body language giveaways that can help “out” someone who’s lying? Back in 2015, University of Michigan researchers identified some common behaviours among liars, including scowling or grimacing, looking directly at the questioner in a bid to appear trustworthy, and overcompensating by gesturing with both hands.

A more recent study, from Erasmus University in Rotterdam, found that liars may unconsciously mimic the body language of those around them while their brains are otherwise engaged in telling lies.

It’s also worth looking out for the “eye dart”: when we glance to the left, we’re attempting to recall facts and events; when we look to the right, we’re thinking more creatively.

"It’s also worth looking out for the “eye dart”: when we glance to the left, we’re attempting to recall facts and events; when we look to the right, we’re thinking more creatively"

What liars sound like

Vocal factors can offer a good clue, too. People who are being deliberately dishonest—or who lack certainty in what they’re saying—tend to speak slower and place less emphasis on the middle of words, according to a study at the Sorbonne University in Paris.

Interestingly, the researchers also found that listeners automatically registered these voice changes as a sign of dishonesty, even when they weren’t being asked to do so.

Earlier studies have suggested that we may know intuitively when someone is lying. It’s important to remember though that none of these pointers offer irrefutable evidence that you’re dealing with a liar. After all, some people just grimace more or speak slower than others.

How to confront a liar

Of course, you may not need to consult any of these tips if you know for a fact that someone is lying to you. But what should you do when faced with a lie?

Instead of accusing someone outright of lying, try “fact-checking” what they’re saying by asking lots of questions. Deceptive people generally can’t provide specifics and their tales start to unravel, say researchers at the University of California. Catch someone out in this way, and it should force a confession or at least kickstart a more honest conversation.

Examine the motive for the lie and remember, it pays to pick your battles. If a friend fakes a headache because they’re afraid you’re going to be angry with them for cancelling a night out, it probably requires a heart-to-heart, rather than an argument. Or ask yourself if you’ve ever done a similar thing to them, and if you have, let it go.

But if you’re dealing with a repeat offender—someone who’s always unreliable and doesn’t give you the respect you deserve—it’s time to rethink the relationship. This needn’t mean confronting their lies in a dramatic showdown, however. It can often feel more cathartic to simply let go and walk away.

Read more: The shocking history of female asylums

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