Psychological Research Inspires New Television Series ‘Lie to Me’

The truth is, we all lie. That’s a basic assumption of the new television series “Lie to Me,” which follows human lie detector Dr. Cal Lightman (played by Tim Roth) as he attempts to solve criminal cases by finding the truth in suspects’ minute facial expressions and gestures.  Lightman is inspired by real-life lie detector, APS Charter Member and Fellow Paul Ekman, who has spent 50 years researching and characterizing facial expressions and body movements. In the past 30 years, his research has focused on how to detect when a person is lying merely by observing tiny, fleeting, and generally involuntary facial expressions and gestures called microexpressions. These microexpressions — a shift of the eyes, a curl of the upper lip, an infinitesimal sneer — can give us away without our knowing it, and Ekman’s cross-cultural research has shown that such furtive little traitors are hard-wired into our biological makeup.

Ekman’s research in the 1960s provided evidence that at least some facial expressions are universal; that is, certain facial expressions signify the same emotion in any culture anywhere in the world. From the modern cultures of South America and Asia to the indigenous tribes of the South Pacific, Ekman demonstrated that people all over the world could recognize the emotions behind the facial expressions of white Americans, such as happiness, sadness, anger, fear and disgust. Encouraged by these findings, Ekman then set out to organize a system by which he could codify the complex facial expressions of any given person.

In 1978, Ekman and his colleague Wallace Friesen published the Facial Action Coding System (FACS), which categorizes facial expressions by the combination of facial muscles that are employed in forming them. There are 43 basic “facial-action units,” and over 10,000 possible combinations of these units. Ekman and Friesen showed that forming certain facial expressions affects blood pressure and pulse rate, and, interestingly, can actually prompt the emotion that corresponds to that expression. This apparent connection between the emotion centers in the brain and the facial muscles suggests that our facial expressions are no easier to control than the emotional experiences that correspond to them.

Through researching how his work on facial expressions might be used to tell whether clinicians’ patients were telling the truth Ekman discovered microexpressions. He began designing a self-teaching program that could help people to recognize microexpressions that might otherwise only be perceptible when slowed down in a video. He founded the Paul Ekman Group, which continues to investigate deception and offers an online training program in microexpressions — the Micro Expression Training Tool, or METT — and various workshops on deception detection (the “Lightman Group” in “Lie to Me” provides similar training programs in the show). The METT, available on Ekman’s website at www.paulekman.com, teaches people how to recognize microexpressions and the emotions behind them in order to help them “relate better, work smarter, and learn what others are really feeling.” As “Lie to Me” shows, Ekman’s work has great potential for applications in law enforcement, especially in criminal interrogation and airport security screening. The Paul Ekman Group continues to investigate how deception detection can be applied to such real-world situations.

Ekman serves as a scientific advisor to the show and posts a weekly blog on his website in which he comments on the science behind each episode’s story lines. He breaks down the conclusions Lightman draws from people’s microexpressions and gives further insight from his research into what exactly Lightman is doing as he investigates criminal suspects. Ekman will also host a special event at this year’s convention in San Francisco entitled “Prime Time Psychology: Science is the Story in ‘Lie to Me,’” during which he and members of the show’s production team and cast will explain how psychological science is used in the show.