Skip to main content

The Mechanism of Human Facial Expression


The Mechanism of Human Facial Expression or an Electrophysiological Analysis of the Expression of the Emotions 
by Guillaume-Benjamin-Amand Duchenne
First published 1862

This work of Duchenne de Boulogne’s is a fascinating interpretation of the ways in which the human face portrays emotions. This book was pivotal in the development of psychology and physiology as it marked the first time that photography had been used to illustrate, and therefore "prove," a series of experiments. Duchenne initiated these pioneering studies on the electrical stimulation of muscles, and was the first person to identify microexpressions. His use of electricity as a physiological investigation tool led this iconographic work which stands at the crossroads of three major discoveries of the 19th century: electricity, physiology and photography. This is best exemplified by his investigation of the mechanisms of human physiognomy in which he used localized faradic stimulation to reproduce various forms of human facial expression. Duchenne remarked that a person in trying to remember something raises his eyebrows, as if to see it, and wrote of joy being expressed with two muscles (zygomaticus major muscle and the orbucularis oculi) contracting to produce a true smile. The ‘Duchenne smile’ is one that engages these muscles. The original book contained over 100 original photographic prints pasted into an accompanying Album.