71. People Can Detect A Fake or Real Smile via Video

Two Types of Muscle Work When We Smile

Thre are two types of muscles that involve contraction when we smile.  zygomatic muscle: This one raises the corner of the mouth. orbicularis oculi muscle: This one raises the cheek and makes the eyes crinkle. 

How A Real or Fake Smile Work

When we genuinely smile, both of the muscles get involved — the corners of our mouths and the cheek raise, our eyes crinkle. This is called Duchenne smiles (because Dr. Guillaume Dunchene searched about it). When we fake a smile, there is only zygomatic muscle active, which means the mouths turn up, but the eyes don't make crinkles. This happens because 80% of us can't consciously control the muscle around the eyes that make them crinkle.

Fake+Real+Smile (binary/octet-stream)

Caption: : Fake (left) vs Real (right) Smile

Don't Make a Smile in a Video to Gain Trust

By looking at the picture, people cannot tell if a person truly smiles or fakes a smile, although that person pretends to smile genuinely.   However, by looking at the video, people can detect a real or fake smile. This is because video can last longer than a snapshot so that people can see all movements on the face and other factors.

Brain Games- Duchenne Smile (Embed)

Caption: : Brain Games