The story
Named after the French physician Guillaume Duchenne de Boulogne (1806–1875) who identified it.
Etymology from Wiktionary, CC BY-SA 4.0.
Duchenne smile
Today it means: A smile involving contraction of both the zygomatic major muscle (which raises the corners of the mouth) and the orbicularis oculi (which raises the cheeks and forms crow's feet around the eyes). Full definition →