Want to Spot a Liar? Science Says Ask Them Questions Like This

Tell the truth. How often do you think people lie? You’ll find all kinds of answers to that question:

• A study from a while back in the Journal of Basic and Applied Social Psychology suggested that lying might be rampant, with 60 percent of people admitting to lying after just a single 10-minute conversation.
• No, says deception expert Timothy Levine of the University of Alabama, Birmingham, whose work is more recent: It’s much less frequent. More like once or twice a day on average.
• But author Pamela Meyer, who wrote a book about lying and gave a super-popular TED Talk on the subject, looks at it the other way, suggesting that most people are on the receiving end of between 10 and and 200 lies every single day.

Truth to tell, I have no idea who is right. Regardless, wouldn’t it would be useful to know with more certainty whether someone is telling the truth?

This is where science comes in.

Writing recently in the peer-reviewed journal, International Journal of Psychology & Behavior Analysis, Aldert Vrij, a professor of applied social psychology at the University of Portsmouth in England, revealed a new study that suggests a simple trick can make it easier to expose liars.

It has to do with finding ways to increase their cognitive load, so that maintaining a lie becomes more difficult. More specifically, Vrij and his colleagues’ work suggests getting people to focus part of their attention on another important concept or task–while you simultaneously question them about whatever you think they might be lying about.

The study involved 164 volunteers who were asked to describe (truthfully) their positions on “various societal topics that were in the news,” as a university summary described it.

Then, the volunteers were divided into two groups: a cohort that would tell the truth when inquired about their feelings by a separate group of interviewers, and a second cohort that was told to lie as convincingly as possible.

From there, the volunteers were further divided into three subgroups:

• One group of volunteers was asked to remember and recall a car registration number–representing a secondary mental task.
• A second group of volunteers was also asked to recall the registration, but they were additionally told that this detail was extremely important, and that they would be penalized if they could not remember it correctly.
• The final group of volunteers had no mention of the car registration at all.

The result? Volunteers who had been instructed to lie, and who were in the second group — the ones who asked to remember the registration and also told that it was important that they do so — were much less likely to be able to deceive the study interviewers than those in either the first or the third groups.

“Our research has shown that truths and lies can sound equally plausible as long as lie tellers are given a good opportunity to think what to say,” Vrij said afterward. “When the opportunity to think becomes less, truths often sound more plausible than lies.”

Vrij is not the first person to suggest that mental distraction might make it harder for people to keep the details of a lie straight. But I think the specifics here make the study especially interesting–and especially if you rely on being able to identify truth-tellers in business.

In short, I think it’s about a strategic approach to the dilemma, rather than a more limited tactical one.

For example, let’s go back to the extremely popular TED Talk we mentioned at the outset by Meyer, which has more than 31 million views. The secrets to revealing liars that she describes are largely about linguistic and behavioral “tells,” such as:

• Non-contracted denials (unexpectedly formal language, like the example she gives of Bill Clinton saying, “I did not have sexual relations with that woman, Miss Lewinsky”), or
• Distancing language, like, “To tell you the truth…” or “In all honesty…”
• Suspicious body language. For example, she says, liars supposedly freeze their upper bodies more often, and can tend to force eye contact.

“Liars will shift their blink rate,” Meyer goes on to say, and “point their feet toward an exit … [and] will take barrier objects and put them between themselves and the person that is interviewing them.”

As intriguing as it all sounds, do you see what I mean about it sounding tactical, rather than strategic?

Even if all of these “tells” did correlate with lying, truth-seekers and serious liars might wind up in a sort of arm’s race, with the best liars discovering the “tells” and then learning not to exhibit them.

With a more strategic approach, like the Portsmouth study, you’re not looking so much for specific behaviors–but instead throwing the less-truthful among us off their game, by adding components that make it harder for them to keep false stories straight in the first place.

Now, Vrig and his colleagues recognize that there are limits to the exact scenario they studied. Certainly, things would get a bit odd if you tried to open a job interview or a business negotiation by asking someone to memorize a car registration number.

But you could add other complexities and mental distractions. A few ideas:

• Perhaps there’s something to the idea of people making deals on the golf course; the game itself might function as the extra mental effort in the Portsmouth study.
• Or else, Vrij suggests introducing a task like “driving a car.” He goes on to day that he means a “simulator;” but why not try to arrange to discuss a potential position with someone while you asked them to drive you somewhere?
• Or else, maybe it’s as easy as pushing for more details in a negotiation when you know that the other side has a deadline or another important task at the same time.

As I write in my free ebook, Neuroscience: 13 Ways to Understand and Train Your Brain for Life, there’s nothing more fascinating than the human brain, and the unexpected ways in which it works.