Shortcut: 4 Ways to Spot a Liar

Have you ever had the feeling someone was lying to you, even though their words rang true? Wouldn’t it be nice to know when a person is telling the truth and when they’re trying to deceive you? Body language experts and law enforcement professionals have devoted countless hours to detecting deception, and they’ve come up with methods to help the rest of us develop an eye for lies. Here are four techniques they recommend.

1: Watch for Physical Signs of Discomfort

Though people lie all the time, they don’t actually like doing so—humans have an instinctive desire to tell the truth, and when we don’t, our brains experience cognitive dissonance that makes us feel stressed, uncomfortable, and anxious.

The key to spotting this internal conflict is to watch for clues in a person’s nonverbal communication. In Read People Like a Book, body language expert Patrick King notes that nonverbal communication comes from the primitive side of our brain—and that side of our brain can’t lie, unlike our more developed, rational side. Thus, the words from our rational brain may say one thing, but our posture, facial expressions, hand movements, and so on, may say something else entirely.

In The Dictionary of Body Language, retired FBI agent Joe Navarro also advises you to pay attention to nonverbal messages, recommending in particular that you watch for repetitive behaviors and self-soothing motions, which could indicate a person is trying to quell internal discomfort. For example, someone might massage their upper arm or shoulder, sway back and forth while sitting, or adjust a hairline or collar (this increases air flow to the body, allowing for cooling off when a person starts to sweat).

2: Watch for Verbal Signs of Discomfort

In Becoming Bulletproof, former Secret Service agent Evy Poumpouras notes that people often reveal clues to internal discomfort not only by how they move but also by how they speak—using certain phrasing or stalling techniques. In particular, watch for when a person:

• Answers your question with a question: If they repeat a question back to you or ask for clarification, they may be stalling.
• Says you’re wasting their time: People may protest, “I don’t have time for this,” when they’re trying to avoid answering questions they’re uncomfortable with.
• Minimizes the issue: If they ask “What’s the big deal?”, they’re often trying to move on from the subject and hoping you will, too.
• Gives overly dramatic answers: When a person swears on their children’s lives or offers some similarly vehement denial, they may be overcompensating to look innocent.
• Uses present tense: When people tell a true story, it’s usually in the past tense. If they use present tense, it may indicate they’re making the story up on the spot.

3. Make Them Mess Up Their Story

King writes that the best way to uncover a lie is to stress the other person’s brain. Lying is mentally taxing, and if a liar is forced to devote more mental energy to their lie than they’d planned, they’re more likely to slip up.

The more they talk, the more opportunities they’ll have to get details wrong—so get them talking. Ask open-ended questions that require long answers. Keep your tone casual so they don’t get defensive. Then, throw them off-balance with specific questions about details of their story. Liars have usually rehearsed their tale but are unprepared to answer questions they haven’t thought through yet.

In Spy the Lie, CIA veterans Philip Houston, Michael Floyd, Susan Carnicero, and Don Tennant likewise advise that you get the other person talking, but they recommend that you do so by asking short, quick questions to encourage quick, instinctive answers that are more likely to lead to slips or inconsistencies. They further caution that you be careful not to ask the wrong questions—for example, don’t repeat questions: If the other person answers (falsely) the same question again and again, it can solidify their lie in their brains.

4: Use the Five-Second Rule

The authors of Spy the Lie also write that you can effectively detect signs of deception by paying careful attention to the five-second period right after you ask a question. In that window, the other person’s answers are direct, instinctive reactions to your questions. If you note a sign of deception outside this timeframe, it might be related to a different factor, and you can’t rely on it as an indicator of a lie.

The Bottom Line

Overall, experts note that spotting a liar takes practice, and they warn against being overly eager to identify deception—what might appear to be a sign of dishonesty might actually be caused by something else, such as a tense environment or a difficult interpersonal dynamic. In addition, it’s important to take a holistic view of a person’s demeanor, as individual body language cues can have multiple meanings. Thus, don’t jump to conclusions, and be cautious about making accusations.

Read the Full Guides

Shortform note: Read the full Shortform guides mentioned in this article here (Image: Toa Heftiba):

• Read People Like a Book
• The Dictionary of Body Language
• Becoming Bulletproof
• Spy the Lie

Join the Conversation

Have you spotted a liar recently—what were the clues? Share your methods in the comments!