Darwin would have loved Botox.
I don’t mean that he would have been first in line at the doctor’s office to get a needle jabbed into his famously furrowed brow. I mean that Darwin would have loved to use Botox as a scientific tool—to eavesdrop on the intimate conversation between the face and brain.
For much of his life, Darwin was obsessed with faces. On a visit to the London Zoo, he gave mirrors to a pair of orangutans and watched them grimace and pucker their lips as they stared at their reflections. He passed many an afternoon gazing intently at photographs of crying babies and laughing women. He showed his friends pictures of a man whose facial muscles were distorted in various ways by electric shocks and quizzed them about what emotion the man seemed to be feeling. To find out if all humans expressed emotions in the same way, he wrote up a list of 16 questions, which he sent to dozens of acquaintances around the world. His list of questions began:
1. Is astonishment expressed by the eyes and mouth being opened wide, and by the eyebrows being raised?
2. Does shame excite a blush when the colour of the skin allows it to be visible? and especially how low down the body does the blush extend?
3. When a man is indignant or defiant does he frown, hold his body and head erect, square his shoulders and clench his fists?
Darwin took the answers he got from his correspondents—from such places as Borneo, Calcutta, and New Zealand—and combined them with the rest of his notes on faces to publish a book in 1872 entitled The Expression of the Emotions in Man and Animals. Most scientists in Darwin’s time considered the face a mystery, its expressions having been set at the time of Creation. But Darwin argued that the look of happiness or grief on a person’s face was the product of evolution, just as our hands evolved from fish fins.
As evidence, Darwin pointed to the results of his poll. People the world over made faces using the same basic patterns of muscle contraction, starting from infancy. In his book Darwin printed pictures of people getting electric shocks, which were taken by the French physician Guillaume-Benjamin-Amand Duchenne. Simply by running current through different parts of a person’s face, Duchenne could produce expressions of happiness, fear, anger, and disgust. Expressions were reflexes, Darwin argued, instinctive patterns etched in our faces and brains.
To trace the history of our faces, Darwin wrote, we need only look at our fellow animals. Although human faces were unique in some ways, they also bore some striking similarities to those of other species: “He who will look at a dog preparing to attack another dog or a man, and at the same animal when caressing his master, or will watch the countenance of a monkey when insulted, and when fondled by his keeper, will be forced to admit that the movements of their features and their gestures are almost as expressive as those of man.”
Darwin described facial expressions as a “language of emotion.” They served as a way for us to communicate before we had words. They helped us not only to understand the emotions of others but to share them as well. “The free expression by outward signs of an emotion intensifies it,” he wrote. “Even the simulation of an emotion tends to arouse it in our minds.”
Darwin’s ideas turned out to be prophetic, but when you read The Expression of Emotions in the 21st century, you can’t help noticing how quaint his scientific research was. Scientists who study faces today do not rely on their pet dogs or letters from friends in Brazil. They trace the development of the face in embryos, scan brains, read the electrical activity of muscles, and record grins and pouts on high-speed video.
Our faces, these scientists have shown, acquired some of their basic form more than half a billion years ago. It was then that early fish evolved muscles on their heads to suck in food and water. All the muscles of our faces develop from a strip of cells at the base of the embryonic head, just as they do in lampreys, which belong to one of the oldest lineages of vertebrates alive today.
The transition to land brought major changes to the faces of our ancestors. They stopped breathing water through gills, and the gill-supporting muscles in the face took on new functions, like controlling the throat to swallow food. At the same time the muscles that moved the jaws became bigger as land vertebrates evolved a more powerful bite.