The Physiology of Lying

By July 18, 2013infidelity


What is your name? No, don’t ignore the question. Play along. There is a point to this.

What is your name? Say it aloud.

Now let’s try it again. But this time, reply with a false name. Any name, just as long as it is a lie. Notice how you actually have to pause to think of a “false name.” There is a reason for that.

Your body processes lies in a completely different way than it does the truth. Telling the truth is a lot easier than lying. Your body is almost instinctive in its response. That’s because it doesn’t have to work as hard as it does when you are telling a lie.

The bigger the lie, the harder it is to pull off. What this means is that you can spot a liar if you are familiar with some of the physiological signs.

Becoming a Human Lie Detector

Contrary to what many people believe, conventional lie detectors are not able to detect lies. Instead, they are built to detect changes in your body’s response to questions. Analysts then use these results to determine if a person is lying. This is an important fact: Lie machines do not ping when they detect a lie. They ping when they detect an abnormal response.

Using the same principle, you can catch people who are lying to you. You may not know a lie when you hear one. However, you will be able to spot a liar when you see one. And the following are some of the ways you can achieve this.

Study the Face

We communicate more with our faces than with any other part of the body. Think about it. It’s hard to tell if someone is upset, happy, or angry by staring at his or her hands or feet. However, with a single glance at a person’s face, you can tell if he or she is feeling any of these emotions.

One of the quickest ways to catch a liar is therefore to study the face. The following are several physiological changes that you might notice.

Watch The Eyes

When people lie, their eyes become unfocused for a few seconds as they try to process a response. You may also notice an unconscious flicker from left to right. Their pupils may narrow.

All of these signs are strong indicators that the person is about to lie to you. Studies conducted by neuro-linguistic programmers reveal that people look up and to the left when they are lying and look up and to the right when they are telling the truth.

Look at the Mouth

Many people try to “smile” their way out of lies. You can spot a fake smile by looking at a person’s facial muscles. The lips will appear to be forced into position, and instead of the eyes becoming relaxed, as they would during a natural smile, they will remain tensed.

People may also unconsciously run their tongues over their teeth or lick their lips several times. Other possible signs to watch out for include a hard swallow. If you ask a question and several of these behaviors accompany the person’s response, he or she is likely lying.

Study the Body’s Response

The face is not the only part of the body that you can observe to detect a lie. You can also gauge a person’s credibility by paying attention to the body’s reaction. Some of the gestures that strongly indicate a person is lying include the following.

Sudden Sweat

Have you heard the phrase “on the hot seat?” It is partially derived from the way that people respond to heavy scrutiny. When people lie, the act puts their bodies under a lot of pressure. In response to this, their metabolisms quicken, sometimes leading to sweat. You’ll notice a thin layer of sweat on their palms and faces.

Persistent Fidgeting

Many people act nervous when they lie. They may tap their feet on the floor, rub their hands across their temples, or rub their noses several times. Liars may also wring their hands, fiddle with nearby objects, or touch their heads. These things are all part of an act meant to dissipate nervous energy. Fidgeting also helps liars hide the fact that they are experiencing stress.


People take defensive stances when they lie. For instance, they may cross their arms or tuck their hands into their pockets. They are also likely to turn their bodies away from you or walk away on some pretext. Their shoulders drop in a slouch, and they use fewer hand gestures.

Listen to the Voice

Listening to someone, you can gauge the person’s sincerity from what he or she says. When people lie, their voices may drop and become less confident. They may stammer over their explanations or ask you questions instead of giving you direct answers.

Most liars become defensive and end up either saying too much or too little. A person’s vocabulary becomes a lot more formal. You will sometimes notice a reduction in the use of contractions and slow, deliberate speech. For instance, instead of saying, “I didn’t,” the person will slowly reply, “I did not.”

Respond Carefully

Not everyone responds the same way to lying. Just as with sports, you will find people who are simply better at hiding lies than others. The key to identifying a liar is to focus on the body’s response. If you can catch three or four signals that suggest a person is lying, then he or she most likely is.

Sometimes, it is best to wait a few days before confronting a liar. This gives you more time to go over the person’s story for holes that you may have missed. It’s also important to note that these behaviors are not always a sign that someone is lying. If your girlfriend’s eyes flicker to the top left, for example, she may simply be staring at a picture over your head—not trying to conceal infidelity.

Finally, it has to be said that there is a downside to being good at detecting a liar—it makes you a good liar, as well.

Call Now