10 signs someone might be lying so you can spot dishonesty early and protect yourself

You’re not alone if you’ve ever wondered how to spot a liar.

Many people think they can easily tell when someone is lying — but research shows that’s not always true.

Catching a lie often has more to do with how blatant the liar is than how skilled we are at spotting deception.

People lie for many reasons, and not every lie is harmful.

Small “white lies,” like saying you like a friend’s haircut, can keep the peace and protect feelings.

But other lies can cause real harm, damaging trust, mental health, and even the justice system that relies on truth.

Why detecting lies is tricky

Dr. Leanne ten Brinke, Associate Professor at UBCO’s Irving K. Barber Faculty of Arts and Social Sciences, has spent years studying lying and deception, UBC noted.

Her research shows that humans aren’t naturally good at catching lies.

“Despite the commonplace nature of deception, humans are poor at detecting lies. Accuracy for deception detection by untrained people is estimated at 54 per cent,” says Dr. ten Brinke. “But because justice often depends on our ability to detect lies, past research focused on behavioural cues to try to detect them.”

Her earlier studies found that people often show multiple subtle signs when they lie — not just one, like a growing nose.

The research identified four main behavioral cues to deception by analyzing emotional TV appeals from people whose relatives had gone missing.

Shockingly, some of these individuals were later found guilty of murder, turning their public pleas into chilling acts of lying.

What new research tells us about how to spot a liar

In a new Law and Human Behavior study, Dr. ten Brinke and her team tested whether those original clues could be applied to new cases to detect lies and identify suspects.

The results showed mixed evidence.

Earlier findings suggested that combining speech analysis with facial expressions could predict truthfulness with very high accuracy.

Subtle signals like a raised eyebrow, a brief smile, or using words like “maybe” or “I guess” were once seen as strong indicators. Each clue added a piece to the puzzle of detecting deception.

But this new study found that while some cues reappeared, others didn’t — and overall, the behaviors were no better at predicting truth than chance.

“Highly motivated liars may try so hard to seem believable that they give off even more signs of deception,” Dr. ten Brinke explains.

Strong emotions in high-pressure situations can make it even harder for liars to fully control their behavior.

10 signs someone might be lying

There is no single clue that proves someone is lying. Still, when certain behaviors are taken together, they can raise quite red flags, especially when they seem out of place or occur suddenly. Experts from Verywell Mind shares the top 10 signs:

1. They stay vague instead of being clear.

Someone who may be lying often avoids details and keeps their answers broad so they do not get caught in a mistake.

2. They repeat the question before answering.

This can be a stalling tactic, giving them extra time to consider their next response.

3. They tell the same story again and again.

Repeating the exact version can suggest they are sticking closely to a prepared explanation.

4. Their sentences come out broken or incomplete.

Speaking in short fragments may signal nervousness or uncertainty about the story.

5. They explain events in a rigid, step-by-step order.

Overly strict timelines can sound forced, as if the story was memorized rather than remembered

6. Their words sound rehearsed.

When answers feel scripted or oddly polished, it may mean they practiced what to say ahead of time.

7. They struggle when asked for specifics.

A story that falls apart under gentle follow-up questions can reveal missing or fabricated details.

8. They avoid simple yes-or-no answers.

Dodging direct questions may be an attempt to keep options open or avoid committing to a lie.

9. They show nervous grooming habits.

Small actions like playing with hair or touching the lips can be signs of stress or discomfort

10. Their body shows signs of stress.

Sweating, fidgeting, muscle tension, or restlessness may reflect a natural fight-or-flight response.

The science behind detecting deception

When learning to spot a liar, experts say it’s essential to look at several signals — not just body language.

Some people focus on eye movements or nervous habits, but research shows these aren’t always reliable.

Psychologist Howard Ehrlichman found that shifting eyes usually means someone is thinking, not lying.

Other studies reveal that liars work hard to control their appearance and sound. They might avoid typical “tells” because they know people are watching for them.

Detecting lies often comes down to analyzing speech content, paying attention to details left out, and sometimes even adding mental challenges — like asking someone to recount events in reverse order — to make lying harder.

Lying is mentally exhausting. It requires remembering what was said, monitoring reactions, and staying consistent.

This mental load can eventually cause cracks in the story that help reveal deception.

How to spot a liar: Understanding the limits

“People often think we can spot a liar through certain speech patterns or facial expressions,” says Dr. ten Brinke. “But this study shows us we shouldn’t rely on signals that work in one group and assume they apply to everyone, especially in high-pressure situations like police interviews. More studies are needed to know what really works, and we may need to take a more personalized approach.”

This finding is important because it reminds us that spotting deception isn’t foolproof.

The ability to detect lies can vary based on the situation, the person, and the stakes involved.

Trust your instincts

Some research suggests that while people struggle to detect lies, they may have an unconscious sense when something feels “off.”

When participants in a study watched interviews with crime suspects, they weren’t great at calling out liars on the spot.

But when researchers measured their automatic reactions, participants were more likely to associate negative words like “dishonest” with the guilty suspects.

This means your gut feeling can sometimes help figure out when someone might be lying — even if you can’t explain precisely why.

How to spot a liar: Key lessons to remember

Learning to spot a liar isn’t about looking for one magic clue. It’s about paying attention to patterns in speech, behavior, and emotional reactions — while remembering that no method is perfect.

Dr. ten Brinke’s work highlights the need for more research to improve our ability to detect lies, especially when the truth matters most.

By combining science, careful observation, and intuition, we may get closer to understanding the complex world of lying and deception.

Watch Pamela Meyer’s powerful TED Talk on “Liespotting” as she reveals the hidden signs of deception and why honesty is worth protecting. (Contains mature content)

Disclaimer: This article is for informational purposes only and is not intended to serve as a substitute for professional advice, diagnosis, or treatment. Always seek the guidance of a qualified expert or licensed professional with any questions or concerns you may have.