How to Tell When Someone Is Lying to You

How to Tell When Someone Is Lying to You
Photo: Janice Storch, Shutterstock

As much as I’d love everyone in my life to only tell the truth, it’s a given that, at least on occasion, someone I know will lie to me. People lie all the time. Public figures do it in public; sometimes with impunity, other times with career-shattering repercussions.

Since lies and liars are an unfortunate fact of life, it’s important to be able to spot them. There are a bunch of common indicators, both non-verbal and verbal, that can help you identify if someone is pulling the wool over your eyes.

Establish a baseline

To determine if someone’s trying to deceive you, you first have to establish a baseline understanding of how that person behaves when they’re being honest. Someone’s baseline is exhibited by their demeanour in mundane and routine situations. Look for a departure from this baseline, whether they’re typically fidgety and scatterbrained or soft-spoken and reserved. In other words, if someone is drastically veering off-course from their normal vibe, then something might be amiss.

If you’re not confident you can establish a baseline — if you suspect they other person lies through their teeth every time they speak — then it might turn out that constant lying is their baseline.

“Context is everything”

Though lies are often best detected via a demonstrable change in someone’s baseline, it’s crucial to remember that “context is everything,” according to Dr. Lillian Glass, the author of The Body Language of Liars. “Just because a person exhibits a specific body language or speech-tell doesn’t mean they are necessarily lying unless it is in the right context,” she writes in an email.

For example, if your typically boisterous and gregarious friend seems quiet and reserved when you ask them an uncomfortable question, it doesn’t necessarily mean they’re lying to you; they could, for example, be wondering if they left the gas running on their stove. Do be aware, if you suspect someone of lying, that many factors could be affecting their behaviour.

However, if someone — say, a notable public figure — is repeatedly accused of lying, no matter the broader context, it might just be that external circumstances don’t matter. For this person, lying might have become habitual.

Change in facial expression

A liar wears their dishonesty on their face. Numerous studies show that people do weird things with their lips and tend to avert their gazes when spewing falsehoods. Someone in the midst of a lie might purse or lick their lips, blink excessively, or “suddenly look away (it doesn’t matter if it’s up, down, or sideways),” Glass writes.

If any of these behaviours stray from the norm, “it may be a good case to assume they are not telling you the truth,” writes Glass. A 2008 study from Stephen Porter’s Forensic Psychology Lab at Dalhousie University in Canada examined the face’s relationship to lying on an in-depth level.

Stephen Porter, one of the study’s lead authors, said at the time:

If someone is telling a really important lie in which the consequences are dire, say life imprisonment, the lie will be revealed anyway. Because unlike body language, you can’t monitor or completely control what’s going on your face.

Body language

There’s a reason detectives and FBI agents pay close attention to the body language of any suspect they interview. It’s because, as Glass says, “the body doesn’t lie.”

When under mental duress, those accused of lying display certain physical behaviours. “Not commonly known, when the human brain is under stress, the brain temperature rises and often is exhibited as perspiration on the forehead or upper lip area of the face,” Roger Strecker, a behavioural analyst and interrogator, told NBC News in 2017.

Speaking to NBC, Strecker noted:

Touching of the face is a ‘pacifier’ and has a calming effect to an otherwise brain under stress. Foot tapping or fidgety hands (when during baseline their hands, legs and feet were benign) should be noted.”

That said, if someone you know or see on TV is constantly accused of lying when asked about anything remotely grounded in reality, there’s a good chance that a lot of this conventional protocol goes out the window.

Log in to comment on this story!