FACS Tells Scientists When You're Faking A Smile

From psychics to lie detectors, humans have always looked for ways to identify when someone is telling the truth. Researcher Paul Ekman may have developed one such method. It's called the Facial Action Coding System, or FACS, and it's surprisingly accurate.

Related: You Might Be Missing Some Facial Muscles

How It Works

To create the system, Ekman and his team created a map of the muscles activated during a wide variety of facial expressions. The FACS labels specific facial movements in Action Units, or AUs: raising the eyebrows is AU 1, for example, while narrowing the eyes is AU 6. To avoid bias, the system only uses numbers, not names, for each expression, and it can detect whether an expression is fake or genuine, voluntary or involuntary, and intentional or spontaneous. Studies have shown that the system can spot a liar with 80% accuracy, and may also detect other important characteristics like heart problems and suicide risk.

Related: Facial Recognition Technology: A Blessing or a Curse?

Real-World Applications

Related: Humans Instinctively Know How And When To Smile

Once you're able to interpret facial expressions with that kind of accuracy, the possibilities are endless. According to Ekman's website, once they're trained to use FACS, people "can utilize these concepts in conjunction with their expertise to benefit those who conduct interviews, interrogations, and business transactions as well as those involved in law enforcement, security, and the legal and healthcare systems with their expert insight and analysis."

Is there something you're curious about? Send us a note or email us at editors (at) curiosity.com. And follow Curiosity on Facebook, Instagram and Twitter.

Watch And Learn: Our Favorite Content About Facial Expressions

Exploring Facial Expressions With Paul Ekman

Where Do Our Facial Expressions Come From?

Can You Spot A Fake Smile?

Written by Curiosity Staff June 24, 2016

Curiosity uses cookies to improve site performance, for analytics and for advertising. By continuing to use our site, you accept our use of cookies, our Privacy Policy and Terms of Use.