DuchenneLächeln

DuchenneLächeln, also known as the Duchenne smile, is a genuine smile that involves the contraction of both the zygomatic major and the orbicularis oculi muscles. The zygomatic major muscle pulls the corners of the mouth upward, while the orbicularis oculi muscle causes the eyes to crinkle, often referred to as "crow's feet." This specific muscular action distinguishes a Duchenne smile from a polite or social smile, which typically only involves the zygomatic major muscle.

The term was coined by the French neurologist Guillaume Duchenne de Boulogne in the mid-19th century. Through his studies using electrical stimulation on facial muscles, Duchenne observed the distinct muscle patterns associated with genuine expressions of happiness. He differentiated between voluntary smiles, which could be produced at will, and involuntary smiles, which he termed "smiles of enjoyment," characterized by the activation of the orbicularis oculi.

Research has indicated that the Duchenne smile is a reliable indicator of positive emotions. Studies have explored its correlation with happiness, life satisfaction, and even longevity. While social smiles can be employed for politeness or to convey positive regard without necessarily experiencing genuine joy, the Duchenne smile is generally considered a more authentic display of positive affect. Its presence is often observed in spontaneous moments of amusement or deep contentment.