A better method for lie detection that anyone can use

Taking a cognitive approach to lie detection can reveal whether the person across from you is fibbing. Research suggests imposing pressure on someone’s working memory, encouraging someone to share more and asking unexpected questions can be more effective than the traditional polygraph approach.

The polygraph is traditionally used to uncover dishonesty by monitoring physiological traits such as blood pressure, pulse, respiration and skin conductivity as someone answers a set of questions. But use of the polygraph has always been controversial; psychologists agree that there’s no evidence that physiological markers are unique to deception. Research suggests there’s a better method for lie detection: the cognitive approach. An article published in Legal and Criminological Psychology provides a meta-analysis of this more recent approach to lie detection, which consists of three techniques: imposing cognitive load (defined as the mental activity imposed on working memory), encouraging someone to share more information and asking unexpected questions. Compared to the polygraph approach to lie detection, the cognitive approach more accurately differentiates between truth and lie.

How can we use lie detection in everyday life? 

Some people are more agreeable than others. These are people whose personalities lean toward compassion and politeness – and who might benefit from having the tools to protect themselves from exploitation. Therapists often use assertiveness training to help agreeable people recognize and cope with more hostile, malevolent or competitive personalities, but the cognitive approach may be another helpful tool for these people to vet the trustworthiness of others. 

If you think you fall into the “agreeable” camp or just want to sharpen your shadiness detection skills, here’s how you can put the cognitive method into practice: 

Encourage someone to recall information relevant to the interaction.

This strategy imposes pressure on the individual’s working memory, and enables you to observe gaps in claims they make. This is especially effective for spotting “gaslighters,” which are individuals who use deception by questioning your recollection of events.

Ask for someone to expand more on relevant topics of interest.

Asking for more information provides clarity around whether the story someone is telling may be false or not. For example, you could use this strategy with a colleague who claims they know more than they do about a subject.

Defy social norms in the interaction and ask unanticipated questions.

Asking unexpected questions ensures that someone is responding from an honest place because answers are not premeditated. For example, an unexpected question could help vet the intentions of a date.

Leveraging the cognitive approach to lie detection equips you with a better tool for assessing someone’s trustworthiness – whether it’s with a partner, friend, colleague or family member. Where could you use these strategies in your life?