top of page

How To Catch A Liar - And Profit By It

Dishonesty in the marketplace costs us all the time. Here’s how to stop buying the line.

By Etelka Lehoczky, Money, 2005

Oh, to be able to detect a lie. Maybe you’re looking to buy a house and you want a straight answer on when the roof was last replaced. Or you’re negotiating with a potential employer and she insists that her salary offer is at the top of the pay scale. Or you’re haggling over leather seats in a new SUV and the salesman swears that he’s losing money on the deal. Everyday life is filled with such moments: situations where success, or failure, at getting to the truth can have a real impact on your pocketbook. And all too often you’re left with the sinking suspicion that your interlocutor got the better of you.

It doesn’t have to be that way, say professional interrogators, jury consultants and other experts specializing in the practice of lie detection. By paying attention to gestures and speech patterns, and by luring your counterpart into contradictions, you can determine when you’re not getting the full story–and turn that knowledge to your advantage.


Doing so isn’t easy. All the experts stress that these techniques are as much art as science, and mastering them takes practice. But we’ve grouped their strategies into four stages, starting with ideas anyone can use right away.


STAGE 1: Don’t Trust Your Instincts

Many of the discoveries that researchers have made run counter to conventional wisdom, so it pays to put aside many of your gut reactions when it comes to distinguishing truth from lies. On one hand, most people place too much faith in others’ basic honesty. One landmark study, by University of Massachusetts Amherst psychologist Robert Feldman, found that a majority of test subjects lied an average of three times in every 10 minutes of conversation.


At the same time, people tend to overrate their ability to distinguish truth from lies. Among other shortcomings, when people think they’re being lied to, there’s a good chance they’re wrong. Researchers have found that the types of body language and behaviors commonly associated with deception, such as fidgeting or failing to hold steady eye contact, are entirely unrelated to a person’s truthfulness. And contrary to the classic cop-show interrogation scenario, honest people are just as rattled by scrutiny as dishonest people are, maybe more so. Confronted with a tough question, a truthful person may stammer, cast around for the right words, correct previous statements, even supply irrelevant and contradictory details. Worst of all, because of the widespread belief in such “tells,” accomplished liars can project honesty by simply avoiding them.


The most sensible approach, then, is a matter of balancing a healthy dose of skepticism about what you’re told with some humility about your instincts.


STAGE 2: Deter the Lies

Given everyone’s natural weaknesses in the lie-detection department, it’s best to try deterring people from lying to you in the first place. Interrogators agree that when you establish a strong posture at the outset of a relationship, your subject will think twice about lying to you. “I can’t control a contractor’s decision to mislead me about the project being on schedule or on budget,” says interrogation specialist Stan Walters by way of example. “The only thing I can do is make myself a harder target.”


Greg Hartley, a former U.S. Army interrogator and author of How to Spot a Liar, says his favorite way to put a subject on the defensive is to respond to virtually every statement with the question, “Really?” Because Hartley seems skeptical about everything the subjects say, they feel they can’t put anything over on him. Private investigator William Fleisher gets a similar reaction by repeatedly asking, “Why?” Deception researcher J. Pete Blair stymies liars by parading his vast knowledge of the topic under discussion, even when it’s not all that vast. Whenever he confronts a salesperson, he’s armed with a thick folder of Web printouts and other materials. Some are about the topic at hand, but others are unrelated documents stuffed in to bulk up his folder. “The first time he pulls one of his salesman tricks, I’ll stop, open it up and slowly look through it,” Blair says. Few people will risk being presented with hard evidence of their own deceit.


STAGE 3: Detect the Lies

Here’s where the techniques get a little subtle. “Observing eye movement is the single most useful tool I’ve ever discovered,” says Hartley. People tend to gaze in one direction when remembering details and a different direction when inventing them, he says. The most common pattern is looking up and to the left when genuinely trying to recall something, and up and to the right when inventing fiction.


That’s far from universal, though, so you’ll need to observe your subject closely to figure out where they tend to gaze. During casual conversation, ask innocuous questions that he ought to be able to answer easily and honestly–and see where he looks. Then watch for the same eye movements when the talk turns to touchier topics. “Say I’m talking to a realtor and I’ve already observed that they look left when they’re recalling something,” he explains. “If I then ask a point-blank question–‘What are the things that are wrong with this house?’–and their eyes start going to the right, it means that they’re creating an answer instead of just recalling one. I’d be very suspicious of that.”


Also, look for giveaway speech patterns. Interrogation specialist Stan Walters listens for telltale phrases that suggest his subject is working overtime to appear credible. When someone emphasizes a statement by saying, “Honestly,” “Believe me,” “Frankly,” “Trust me,” “You’re not going to believe this,” or “Why would I lie?” he’s telling you that he doesn’t really believe his own words.


And remember that truth-telling often looks messier than lying. “When you’re talking to someone and you realize you’ve said something that wasn’t quite right, you’ll go back and fix it. That’s what people do when they’re telling the truth,” says UC–Santa Barbara’s Bella DePaulo, who studies the psychology of lying. “When people are lying, they’re worried that those kinds of admissions will give it away. They’re reluctant to say, ‘Oh, wait, let me correct that.'” On the contrary, liars will often stick to a well-rehearsed patter designed to impress you with competence while distracting from unsavory details.


STAGE 4: Zero In on the Truth

Tempting though it may be to say “Gotcha!” when you detect deceptive behavior, it won’t help you figure out exactly what your subject is covering up. “You don’t want your interview to turn into an interrogation,” says Blair. “If I accuse you of lying, I’ve just jacked you up. Whether you’re innocent or guilty, you’re going to have the same nervous reactions because you’re under a lot of pressure.”


Instead, try Hartley’s “scattershot” technique. Ask lots of seemingly disconnected questions, jumping from topic to topic, to throw your subject off stride. All the while, keep circling back unobtrusively to the areas she seems inclined to avoid. If she keeps repeating the same information, using the same words, without providing any additional facts or examples, you’ll know you’re closing in on the precise nature of the lie.


Even if you never eke out the full truth this way, you will know whether or not you want to do business with the person. In most day-to-day scenarios, that’s a battle won.

bottom of page