How to know if someone is lying

A 2010 survey by the Science Museum found the average British man tells 1,092 lies a year, typically about his whereabouts, drinking habits or feelings. The survey found the average women tells a mere 728 annual lies, often about her spending habits or the way she treats her partner's belongings. As we all have so much practice, it can be hard to spot when people are spinning you a line. Look out for these tell-tale signs though and you'll soon get at the truth.


Ask questions about the details of any suspect account you are given. Often, the small embellishments a liar adds are inconsistent. If you spot tiny inconsistencies, you're unlikely to be hearing the exact truth. As the ancient Roman orator Quintilian observed, liars need good memories. It's in the little details that our invention lets us down.


Look for signs of anxiety that are otherwise hard to explain in the person speaking to you. Sweating or fidgeting for no obvious reason are classic signs of someone telling a lie. Look out for tapping fingers and jiggling feet too, both signs of unease and a lack of candour.

Eye contact

Observe whether or not the speaker can maintain eye contact. People often unconsciously glance away or break eye contact when they tell lies, according to sources at the New York Police Department and the CIA interviewed by Forbes magazine. Dilated pupils may also indicate lying, so check your speaker's eyes closely.

Eyes right

Note the direction of the speaker's gaze and you may gain a vital clue. A theory known as "Neuro Linguistic Programming" suggests our gaze unconsciously drifts to the right when we recall information and to the left when we invent it. Someone who often looks to the left may be trying to deceive you.


Note any unusual pauses in the speaker's account. We all hesitate from time to time when we speak, but if we have to make something up, we often play for time, as we feverishly invent a plausible story. Liars often pause to think through circumstances an honest speaker would simply remember.

Online honesty

Check text carefully to assess someone's honesty online. Psychology Today reports a 2012 study of internet dating profiles found online liars use the word "I" as little as possible and negative constructions like "not boring" rather than positive ones such as "interesting". Dodgy posters also tend to be evasive, writing as little as possible to avoid committing themselves.

Mixed messages

Spot a mismatch between what people say and their posture and you've probably caught them lying. Someone who smiles, nods and says "Yes" but simultaneously shrugs is really saying "No". Body language expert Robert Phipps told MSN, "You're looking for consistency in body language." If the words fit the gestures, you're probably hearing the truth.

Hidden hands

Pay attention to the speaker's hands. Open palms suggest sincerity. But if speakers lay their hands flat or hide their palms, for example by crossing their arms, they may be trying to conceal something. Liars often press their lips or play with their hair too, according to psychologist Professor R. Edward Geiselman.

bibliography-icon icon for annotation tool Cite this Article

About the Author

British writer Martin Malcolm specializes in children's nonfiction. His books include "A Giant in Ancient Egypt" and "Poetry By Numbers." His schoolkids' campaign for the Red Cross won the 2008 Charity Award. A qualified teacher, he has written for the BBC and MTV. He holds a Master of Arts in English from the University of London.