/ |

Reading the mind through the face


Victorian Englishmen were not known for feeling comfortable displaying their emotions. Charles Darwin, exceptional in so many other ways, was like his countrymen in this regard, and considered the display of emotions in adult humans to be vestigial, something left over from our evolutionary past. That didn’t stop him from publishing, in 1872, what remains the most comprehensive text on the nature of emotions.

In “The Expression of the Emotions in Man and Animals,” Darwin argued that like any other trait, emotions and emotional expressions had evolved by natural selection. Ever observant, Darwin had noticed how his dog would go happily before him as he left his house, anticipating being taken for a long walk. But often Darwin would instead take a path that led to his hothouse, containing his experimental plants.

“The instantaneous and complete change of expression which came over him as soon as my body swerved in the least towards the path (and I sometimes tried this as an experiment) was laughable,” wrote Darwin. “His look of dejection was known to every member of the family, and was called his hot-house face. This consisted in the head drooping much, the whole body sinking a little and remaining motionless; the ears and tail falling suddenly down, but the tail was by no means wagged.”

What interested Darwin, however, was whether his dog had learned to show those expressions when he was thwarted of a walk, or whether they were innate, something that all dogs automatically displayed.

He concluded that dogs — and all animals that show emotions, including humans — have the innate ability to express emotions, and that the displays are universal. So a smile from an Australian aboriginal means the same as it does from a London barrowboy or a teenager in Shibuya (if they ever smile).

Surprisingly, the concept of universal emotional expression was one that foundered. Darwin’s book was initially a best seller, but soon fell into disregard. Debate raged back and forth on this issue: Are emotions the result of nature, or of nurture? It is only relatively recently that the matter has been resolved.

In the 1960s, Paul Ekman, now professor of psychology at the University of California Medical School, San Francisco, decided to gather data that would settle the argument. He conducted fieldwork to investigate universal facial expressions, traveling in the United States, Japan, Brazil and Papua New Guinea.

“I wanted to finally settle the argument about whether emotions are culturally specific or universal and I found that Darwin was right,” said Ekman. “There are at least seven emotions that have the same signals for all humans, regardless of their heritage, nationality or language.”

But Darwin, vindicated once again, was probably wrong about the function of emotions in humans. He considered that emotions in adult humans were no longer functional. We exhibit facial expressions “though they may not be of the least use,” he wrote.

Imagine if we could never see the people we talk to, say if we were blind or if everyone wore full-face masks, or veils. That helps us realize the amount of information we get just from seeing someone’s face. Blind people probably develop a more perceptive sense of hearing, and glean information about someone’s emotional state from their voice, but many emotions are transmitted visually.

Ekman has done more than most to show how emotional expressions are used. He has acted as consultant on the subject to U.S. government agencies such as the FBI, the CIA and the ATF; to lawyers, judges, and police, and to corporations, including the animation studios Pixar and Industrial Light and Magic.

One of his papers, published in Nature in 2000, tested the ability to spot liars. Ekman and colleagues found that people with aphasia — a loss in language ability resulting from a stroke or other type of brain damage — apparently have a strong advantage in spotting liars, particular when the untruths are given away by changes in facial expression.

Coauthor Nancy Etcoff, a psychologist at the Massachusetts General Hospital, used a series of videotapes prepared by Ekman and Mark Frank, of Rutgers University. Volunteers had been videotaped twice talking about their emotional state in a positive way. In one instance they were looking at a pleasant scene and telling the truth, in the other they were looking at distressing scenes and lying about their emotional state. The tapes had been analyzed previously in Ekman’s lab to identify subtle changes in facial expression or changes in vocal pitch associated with the untruthful interview.

The videotapes were shown to four groups of participants. One group consisted of patients with significant aphasia as a result of damage to the left sides of their brains. The other groups were: patients with damage to the right of their brains and no language difficulty; healthy control subjects; and a group of college students. The participants were informed that one of each pair of interviews was untruthful, and were asked to identify when the volunteers were lying and when they were telling the truth.

Previous research has shown that people usually have only a 50/50 chance of detecting when someone is lying by their expression or tone of voice. But the aphasia patients were able to detect lies cued by facial expression alone 73 percent of the time. The other study groups all had close to 50 percent accuracy in recognizing lies tied to facial expressions.

The Danish physicist Niels Bohr said, “Never express yourself more clearly than you think.” But Ekman — and those aphasia patients — might be able to read your expressions before you have had a chance to even know what you think.