10 Ways to Catch a Liar (2024)

J.J. Newberry was a trained federal agent, skilled in the art of deception detection. So when a witness to a shooting sat in front of him and tried to tell him that when they heard gunshots they didn't look, they just ran -- he knew they were lying.

How did Newberry reach this conclusion? The answer is by recognizing telltale signs that a person isn't being honest, like inconsistencies in a story, behavior that's different from a person's norm, or too much detail in an explanation.

While using these signs to catch a liar takes extensive training and practice, it's no longer only for authorities like Newberry. Now, the average person can become adept at identifying dishonesty, and it's not as hard as you might think. Experts tell WebMD the top 10 ways to let the truth be known.

Tip No. 1: Inconsistencies

"When you want to know if someone is lying, look for inconsistencies in what they are saying," says Newberry, who was a federal agent for 30 years and a police officer for five.

When the woman he was questioning said they ran and hid after hearing gunshots -- without looking -- Newberry saw the inconsistency immediately.

"There was something that just didn't fit," says Newberry. "She heard gunshots but she didn't look? I knew that was inconsistent with how a person would respond to a situation like that."

So when they weren't paying attention, he banged on the table. They looked right at him.

"When a person hears a noise, it's a natural reaction to look toward it," Newberry tells WebMD. "I knew she heard those gunshots, looked in the direction from which they came, saw the shooter, and then ran."

Sure enough, he was right.

"Her story was just illogical," says Newberry. "And that's what you should look for when you're talking to someone who isn't being truthful. Are there inconsistencies that just don't fit?"

Tip No. 2: Ask the Unexpected

"About 4% of people are accomplished liars and they can do it well," says Newberry. "But because there are no Pinocchio responses to a lie, you have to catch them in it."

Sir Walter Scott put it best: "Oh what a tangled web we weave, when first we practice to deceive!" But how can you a catch a person in their own web of lies?

"Watch them carefully," says Newberry. "And then when they don't expect it, ask them one question that they are not prepared to answer to trip them up."

Tip No. 3: Gauge Against a Baseline

"One of the most important indicators of dishonesty is changes in behavior," says Maureen O'Sullivan, PhD, a professor of psychology at the University of San Francisco. "You want to pay attention to someone who is generally anxious, but now looks calm. Or, someone who is generally calm but now looks anxious."

The trick, explains O'Sullivan, is to gauge their behavior against a baseline. Is a person's behavior falling away from how they would normally act? If it is, that could mean that something is up.

Tip No. 4: Look for Insincere Emotions

"Most people can't fake smile," says O'Sullivan. "The timing will be wrong, it will be held too long, or it will be blended with other things. Maybe it will be a combination of an angry face with a smile; you can tell because their lips are smaller and less full than in a sincere smile."

These fake emotions are a good indicator that something has gone afoul.

Tip No. 5: Pay Attention to Gut Reactions

"People say, 'Oh, it was a gut reaction or women's intuition,' but what I think they are picking up on are the deviations of true emotions," O'Sullivan tells WebMD.

While an average person might not know what it is he's seeing when he thinks someone isn't being honest and attribute his suspicion to instinct, a scientist would be able to pinpoint it exactly -- which leads us to tip no. 6.

Tip No. 6: Watch for Microexpressions

When Joe Schmo has a gut feeling, Paul Ekman, a renowned expert in lie detection, sees microexpressions.

"A microexpression is a very brief expression, usually about a 25th of a second, that is always a concealed emotion," says Ekman, PhD, professor emeritus of psychology at the University of California Medical School in San Francisco.

So when a person is acting happy, but in actuality is really upset about something, for instance, their true emotion will be revealed in a subconscious flash of anger on their face. Whether the concealed emotion is fear, anger, happiness, or jealousy, that feeling will appear on the face in the blink of an eye. The trick is to see it.

"Almost everyone -- 99% of those we've tested in about 10,000 people -- won't see them," says Ekman. "But it can be taught."

In fact, in less than an hour, the average person can learn to see microexpressions.

Tip No. 7: Look for Contradictions

"The general rule is anything that a person does with their voice or their gesture that doesn't fit the words they are saying can indicate a lie," says Ekman. "For example, this is going to sound amazing, but it is true. Sometimes when people are lying and saying, 'Yes, she's the one that took the money,' they will without knowing it make a slight head shake 'no.' That's a gesture and it completely contradicts what they're saying in words."

These contradictions, explains Ekman, can be between the voice and the words, the gesture and the voice, the gesture and the words, or the face and the words.

"It's some aspect of demeanor that is contradicting another aspect," Ekman tells WebMD.

Tip No. 8: A Sense of Unease

"When someone isn't making eye contact and that's against how they normally act, it can mean they're not being honest," says Jenn Berman, PhD, a psychologist in private practice. "They look away, they're sweating, they look uneasy ... anything that isn't normal and indicates anxiety."

Tip No. 9: Too Much Detail

"When you say to someone, 'Oh, where were you?' and they say, 'I went to the store and I needed to get eggs and milk and sugar and I almost hit a dog so I had to go slow,' and on and on, they're giving you too much detail," says Berman.

Too much detail could mean they've put a lot of thought into how they're going to get out of a situation and they've crafted a complicated lie as a solution.

Tip No. 10: Don't Ignore the Truth

"It's more important to recognize when someone is telling the truth than telling a lie because people can look like they're lying but be telling truth," says Newberry.

While it sounds confusing, finding the truth buried under a lie can sometimes help find the answer to an important question: Why is a person lying?

These 10 truth tips, experts agree, all help detect deception. What they don't do is tell you why a person is lying and what the lie means.

"Microexpressions don't tell you the reason," says Ekman. "They just tell you what the concealed emotion is and that there is an emotion being concealed."

When you think someone is lying, you have to either know the person well enough to understand why they might lie, or be a people expert.

"You can see a microexpression, but you have to have more social-emotional intelligence on people to use it accurately," says O'Sullivan. "You have to be a good judge of people to understand what it means."

Extra Tip: Be Trusting

"In general we have a choice about which stance we take in life," says Ekman. "If we take a suspicious stance life is not going to be too pleasant, but we won't get misled very often. If we take a trusting stance, life is going to be a lot more pleasant but sometimes we are going to be taken in. As a parent or a friend, you're much better off being trusting rather than looking for lies all the time."