11 Ways To Tell If Someone Is Telling You The Truth, According To Science (2024)

Wouldn’t the world be such a simple place if someone’s nose really grew when they told a lie? Then we wouldn’t have to spend so much time trying to determine whether people are telling the truth. Luckily, though, there are scientific ways to tell if someone is being honest that can guide us in the right direction. The signs of honesty, which we'll get to below, are a combination of both verbal and non-verbal cues that all are dead giveaways, based on research and practice.

It can be nothing short of frustrating when we feel someone might be lying to us, but we can’t seem to get to the bottom of whether they are really telling the truth or fibbing. Lies can be thrown at us by countless people in our lives — from friends, to family, to significant others, coworkers and more. Sometimes the lies are tiny little white ones — like, “I love your new dress,” or “No, your hair doesn’t look messy today” — but, other times they might be big and very significant — like, “No, I didn’t cheat on you,” or “It wasn’t me who stole money from you.” When considering the latter group of lies, I’m sure many of us can agree that it's vital to be able to tell if the person is telling us the truth or not. For that reason, let’s discuss some tactics that could be helpful in cracking the case. Here are 11 scientific ways to tell if someone is telling you the truth.

1. Their Story Is Longer & Detailed

If you’re suspecting someone is lying, yet they tell you a story that is lengthy, complete, and fully detailed, it’s likely they’re actually telling the truth, according to Psychology Today. The outlet said a short story, or one that seems to be strung together and incomplete, might tend to be one that is fabricated.

2. They’re Holding The Right Amount Of Eye Contact

Eyes have the power to be extremely telling at times, particularly when it comes to whether people are telling the truth or not. When I think about it, I assume liars would have a difficult time holding eye contact, but it turns out the opposite is true. According to research reported on in Psychology Today, “liars maintain more deliberate eye contact than do truthful people.” With that in mind, pay attention to the eye contact the person in question is maintaining with you — if it doesn’t feel like a complete stare down, and rather is moments of eye contact followed by glances away, it could be a sign they’re being genuine.

3. Their Breathing Is Steady

Business Insider spoke to Dr. Lillian Glass, a behavioral analyst and body language expert and author of The Body Language of Liars, who said someone who is lying to you may begin to breathe heavily as they’re speaking. “In essence, they are out of breath because their heart rate and blood flow change,” Glass said of liars. “Your body experiences these types of changes when you’re nervous and feeling tense — when you lie.” Is the person you’re speaking with maintaining steady breathing? The words they’re speaking could likely be the truth.

4. Their Voice Is Steady, Too

In addition to steady breathing, those who are telling the truth also tend to have a steady speaking voice. Real Simple spoke to Gregg McCrary, a retired FBI criminal profiler and a crime analyst in Fredericksburg, VA, who said it’s important to first pick up on how the person usually speaks (animated, subdued, etc.) and then take note of if their voice is changing as they tell certain parts of a story. If their voice is steady, it’s a good indication the person is telling the truth.

5. They Neglect To Blame Negative Outside Forces

While liars tend to use negative outside forces as excuses (e.g., “I’m late again because there was so much traffic”), truth tellers are less likely to do so. Fox News Magazine quoted Noah Zanden, science communicator and chief executive of Quantified Communications, who said liars will tend to blame these outside forces because deep down — on some level — they might actually feel guilty about the fact that what they’re saying isn’t true. Listen closely to the person you’re speaking with. Are they constantly blaming in this way? If not, they might be in the clear.

6. You Haven’t Noticed Them Touching Their Nose

Watch the person’s hands. Are they reaching up and touching their nose as they’re speaking? Nose touching is a sign of fibbing, according to Dr. Alan Hirsch of The Smell & Taste Treatment and Research Foundation in Chicago. This is because certain tissues in the nose usually engorge when a person is telling a lie, releasing histamine and making the nose itch. If the person hasn’t been touching their nose at all, take this as a good sign.

7. They’re Not Covering Their Throat

Likewise, hands will cover certain “vulnerable” body parts when someone is telling a lie, according to Glass. Glass told Business Insider the areas liars tend to cover include their throat, head, abdomen, or chest. On the flip side, truth tellers won’t have the urge to do so, so watch their body movements and take note of how they’re moving and what they’re covering.

8. Their Rate Of Blinking Doesn’t Change

Back to the eyes for a moment — blinking is a very easy way to detect if someone is telling you the truth. Those who are being honest will maintain a consistent rhythm of blinking as they’re speaking to you. Oppositely, according to research discussed by the Daily Mail, a liar will blink more slowly when they’re telling a lie, and then the blinking speed will increase up to eight time faster than normal after the lie has been told.

9. They’re Speaking In Complete Sentences

According to research out of UCLA on the topic of lying, liars tend to use sentence fragments more often while speaking, while truth tellers tend to speak in complete sentences. So, in addition to picking up on the non-verbal cues we’ve discussed already in detail, be sure to pay attention to how the person is forming sentences.

10. There’s No Fake Smile In Sight

A genuine smile (that which engages the eye muscles) is good. A fake smile could mean something is up. The Telegraph reported on a study that showed one of the body movements associated with a lie is a fake smile. Why? According to the study, liars have an “increased activity of the ‘zygomatic major muscles’, located around the mouth,” and it can force the face into a fake smile.

11. Your Instincts Are Telling You It’s The Truth

Did anyone ever tell you you should follow your instincts? Turns out that when we’re deciding whether to trust someone or not, we really should rely on those automatic instincts we have after all. According to research out of the Haas School of Business at the University of California, Berkeley, our instincts for determining whether someone is lying or telling the truth are fairly strong. The research showed, rather, that it’s our conscious minds that sometimes let us judge the situation the wrong way. If you have that gut feeling either way, listen to it.

Now that you’re schooled on some of the tell tale signs someone is being honest, you might be pleasantly surprised to learn the people around you are more truthful than you might have imagined. We al know not everyone is going to tell the truth all of the time, so at least now we can more easily detect when stories or statements are honest, or big ‘ol fibs.

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