Have you ever taken a second look at someone smiling at you and thought to yourself, “they’re faking it”, but couldn’t put your finger on exactly what made you believe they were smiling insincerely?

Turns out there’s one biological tell you can look for that will let you know for sure whether someone is smiling for real, or just giving you Lip Service…

According to the insightful Marianne LeFrance who authored a compelling book all about the science behind our smiles titled Lip Service, there are actually several anatomical tells that we involuntarily give that can be mimicked. One of those anatomical muscle tells, however, is much harder to isolate, and nearly impossible to summon on fake command, and that’s the orbicularis occuli that encircles the eye socket.

When people genuinely smile in a true burst of positive emotion, the corners of their mouth (controlled by the zygomaticus major which can be faked) contract, and the orbicularis oculi creates the crows feet wrinkles that fan out from the outer corners of the eyes. Most people can’t do that deliberately, and most people don’t pay close attention to it, so it’s easy to miss the tell.

From Brainpickings: From Darwin’s famous early dabbles in the science of facial expressions to Duchenne’s legacy, from evidence of babies practicing smiling in the womb to studies suggesting a positive correlation between smiling and longevity, LaFrance blends a researcher’s rigor with a social scientist’s humanism in an intelligent yet highly readable narrative, complete with 38 illuminating black-and-white illustrations. LaFrance writes:

“Smiles are universally recognized and understood for what they show and convey, yet not necessarily for what they do. Smiles are much more than cheerful expressions. They are social acts with consequences.”

Food for thought.

*Image: Facial expressions triggered by electric stimulation, from Mécanisme de la Physionomie Humaine by Guillaume Duchenne, 1862. Public domain image via Wikimedia Commons.