mind & bodyThe Public Domain Review1862 · Paris, France
In 1862 Duchenne used electric shocks on faces to map which muscles create each expression
Benjamin Duchenne de Boulogne applied electrodes to the faces of volunteers and used small electric currents to contract individual facial muscles. He found that specific muscles produce specific expressions, and he treated each muscle as a unit of feeling. His 1862 book listed 53 emotions that could be described through muscle movements. The work was an early attempt to link facial anatomy to emotion, and it produced photographs that later shaped how researchers studied expression.
Electrical stimulation makes a single facial muscle contract, so the expression it produces can be seen in isolation. By testing many muscles one at a time, Duchenne could tie specific movements to specific emotional looks.
Duchenne's work was an early bridge between physiology and psychology of emotion, and it fed into Darwin's later studies of expression. Researchers still use the distinction he drew between a genuine smile, which involves the muscles around the eyes, and a polite one.
The 'Duchenne smile', a genuine smile that engages the eye muscles, is named after him.
Image: The Public Domain Review
