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.