homehome Home chatchat Notifications


How to spot a liar: three cognitive techniques from science

Lying and washing the dishes at the same time can expose a deception.

Tibi Puiu
December 10, 2021 @ 7:12 pm

share Share

Credit: Flickr, Tristan Schmurr.

There are many reasons why people lie. One of them is that it just works — because most people are terrible at detecting deceptive statements. Of course, there are certain techniques that can help turn the tables, which professionals in law enforcement, for instance, routinely use. However, that doesn’t mean you need to buy a polygraph or graduate special FBI training in order to become better at spotting lies.

In recent years, research has highlighted the role of the cognitive approach when it comes to lie detection, offering tools that are accessible to virtually anyone.

This ‘cognitive approach’ refers to active interviewing tactics that are designed to single out deceptive behavior. This approach builds on the idea that lying is much more cognitively demanding than telling the truth since you always have to keep tabs on your lies so you don’t get entangled in them.

A pair of psychologists at the University of Gothenburg in Sweden reviewed 23 previously conducted studies on the subject — known as a meta-analysis — which together summed nearly 3,000 participants.

They found that the cognitive approach to lie detection had an average accuracy rate of only 52% in naïve observers, which is a little better than chance. However, informed observers (those who were informed about which deception cues to focus on) had an average accuracy of nearly 75%.

“The central tenet of the cognitive approach is to ask questions that make a liar’s already demanding task even more demanding. Ideally, these questions should have minimal impact on a truth teller’s ability to provide a statement. It is argued that this differential increase in difficulty for liars will increase verbal differences between true and false statements, compared to standard interviewing methods,” wrote the researchers in the journal Applied Cognitive Psychology.

The researchers go on to mention three interviewing techniques classed under the cognitive approach to deception that anyone can use.

1. Imposing cognitive load

This technique involves introducing external stimuli that make it more challenging to allocate cognitive energy required to maintain a lie.

Some of the things you can try are asking the interviewee to provide their statement in reverse order or to maintain eye contact at all times. Another nifty trick is asking the interviewee to perform a secondary task that takes up mental energy while providing a statement. Something as simple as washing the dishes while talking can be enough to put a liar on the wrong foot.

“Tasks designed to increase cognitive load will impair liars’ ability to provide a statement more so than that of truth-tellers. This is because lying is already a more demanding task,” the researchers wrote.

2. Encouraging the interviewee to say more

Inspired by memory-enhancing methods developed within eyewitness research, some studies suggest that encouraging the interviewee to do more talking can enhance deception detection. The more details a liar offers, the greater the odds of making a contradiction that can signal deception.

“It is argued that truth-tellers will be able to provide more information when encouraged to do so, since their statements will be based on real memories of an event. In contrast, liars are expected to find this task difficult, as they will be required to fabricate more detailed information on‐the‐spot,” the researchers in Sweden wrote.

3. Asking unanticipated questions

Liars are good at anticipating questions meant to check the veracity of their statements and will prepare fabricated details to support their deception. According to previous research, prepared lies are much harder to distinguish from the truth than unprepared lies.

So the idea is to catch a liar off guard by asking questions they haven’t anticipated, but which a person telling the truth will have no difficulty answering on the spot.

“It is argued that for unanticipated questions truth-tellers should provide more information and more consistent answers, in group and repeated interviewing situations, compared to liars,” the researchers wrote.

The authors of the meta-review mention that the cognitive approach seems to be effective as long as observers are trained on which cues to focus. ” Although numerous questions persist, this result suggests potentially promising paths forward for this innovative area of deception research,” they added.

share Share

The secret to making plant-based milk tastier and healthier: bacteria

Instead of masking off flavors with sugar, salt, or artificial additives, companies can let bacteria do the work.

A 30,000-Year-Old Feather Is a First-of-Its-Kind Fossil

A new analysis of a fossil found in 1889 has unveiled the presence of zeolites—and an entirely new mineralization method.

This Sensor Box Can Detect Deadly Bird Flu in 5 Minutes. But It Won't Stop the Current Outbreak

The biosensor can detect viral airborne particles.

In 2013, dolphins in Florida starved. Now, we know why

The culprit is a very familiar one. It's us.

Researchers can't rule out the possibility of life existing on Titan

It wouldn't be very much, but it's exciting anyway.

The Earth's oceans were once green. Then, cyanobacteria and iron came in

A pale green dot?

Could man's best friend be an environmental foe?

Even good boys and girls can disrupt wildlife in ways you never expected.

Musk's DOGE Fires Federal Office That Regulates Tesla's Self-Driving Cars

Mass firings hit regulators overseeing self-driving cars. How convenient.

Archaeologists Just Found a Stunning Teotihuacan Altar Hidden in a Maya City. Its Murals Tell a Shocking Story

What were these outsiders doing so far away from home?

These Strange-Looking Urinals Could Finally Stop Pee From Splashing Back on You

The humble urinal gets a much needed high-tech update after 100 years.