Can You Spot a Patient’s Lie?


While we might like to think we have what it takes to determine whether someone is lying or telling the truth, research shows it’s not that easy.

It turns out that a poker face really does work when it comes to hiding the truth. Most of us would like to think that we have what it takes to be able to identify whether someone is lying or telling the truth. But, researchers from Princeton University have discovered that most people make an instantaneous and fairly uncomplicated judgment about the honesty of statements. It turns out that angry facial expressions give the impression of dishonesty, while happy facial expressions send a message of honesty. These results suggest that it is all too simple for a person to effectively tell a lie and achieve the intended goal of making that lie believable. The study results also imply that it would be relatively easy for a person who repeatedly practices telling lies to learn how to control his or her own facial expressions to give the impression of trustworthiness, and to perfect those facial expressions based on the positive and negative responses to his or her lies. 

Making a Poker Face Starts in Childhood and Transcends Cultural Barriers 

Researchers from the University of Valencia, in Valencia, Spain, studied the ability of adults to detect whether children were lying. Adult study participants were shown videos of children making honest or dishonest statements. As it turned out, adults were not successful when it came to accurately detecting lies if the children in the videos showed less emotion in their facial expressions. Adults were better able to distinguish the truthful from the untruthful statements when the children in the videos showed more emotional facial expressions. 

Men and Lie Detecting Capabilities vs. Women and Lie Detecting Capabilities 

Another interesting observation that came out of the Spanish study results was that men and women had different outcomes when it came to accurately detecting the children’s lies. Men were more likely to pick up on the children’s dishonest statements, while women were slightly more likely to accurately identify the children’s true statements. So, men could catch a lying child better than women could, but they were more apt to mistake a truthful statement for an untruthful statement.

What Does This Mean? 

Unfortunately, these generalized tendencies when it comes to spotting lies probably mean that it is not particularly difficult for someone to learn to mask dishonest statements, even at a fairly young age. If an individual discovers how to lie effectively by learning how to produce an expressionless face, or even learns how to lie effectively by producing a happy looking smile, then it is highly probable that those who are untrained in recognizing lies and who are less cynical to begin with, will fail to identify the lie when faced with a poker face or with a well practiced liar. Of course, lying can result in unintended consequences for the victim. Physicians, like all professionals, may face problems when believing a ‘lie’ in the work setting.

Do you think that doctors should receive training in lie detection as a part of the medical school curriculum?


Gadea M, et al. Deceit and facial expression in children: the enabling role of the “poker face” child and the dependent personality of the detector. Front Psychol. 2015 Jul 28;6:1089.

Todorov A. Evaluating faces on trustworthiness: an extension of systems for recognition of emotions signaling approach/avoidance behaviors. Ann N Y Acad Sci. 2008 Mar;1124:208-24.

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