The Duchenne Smile is named after the French neurologist Duchenne de Boulogne who conducted pioneering research into the science of electrophysiology.
As part of a series of experiments which involved stimulating the facial muscles of test subjects with electrical currents Duchenne discovered that two specific facial muscles have to work together in order to produce a genuine smile, namely: The zygomatic major muscle which turns the corners of the lips up, and the orbicularis oculi muscle which contracts around the eyes resulting in the appearance of distinctive wrinkles commonly referred to as crows feet.
Fake Smile (only using the zygomatic major muscle)
(Photo Credit: Mick & Wout)
Genuine Smile (using both the the zygomatic major muscle and the orbicularis oculi muscle)
(Photo Credit: Eric McGregor)
Can you tell a real smile from a fake one?
Now you know all about the Duchenne smile why not put your new found body language knowledge to the test. Check out this online experiment based on research by Professor Paul Ekman which is designed to see whether you can spot the difference between a fake smile and a genuine smile.