What Ekman is saying is that the face is an enormously rich source of information about emotion. In fact, he makes an even bolder claim—one central to understanding how mind reading works—and that is that the information on our face is not just a signal of what is going on inside our mind. In a certain sense, it is what is going on inside our mind.
The beginnings of this insight came when Ekman and Friesen were first sitting across from each other, working on expressions of anger and distress. “It was weeks before one of us finally admitted feeling terrible after a session… They then went back and began monitoring their bodies during particular facial movements… “What we discovered is that that expression alone is sufficient to create marked changes in the autonomic nervous system.
… We weren’t expecting this at all. And it happened to both of us. We felt terrible. What we were generating were sadness, anguish. And when I lower my brows, which is [action unit] four, and raise the upper eyelid, which is five, and narrow the eyelids, which is seven, and press the lips together, which is twenty-four, I’m generating anger. My heartbeat will go up ten to twelve beats. My hands will get hot. As I do it, I can’t disconnect from the system. It’s very unpleasant, very unpleasant.”
Ekman, Friesen, and another colleague, Robert Levenson (who has also collaborated for years with John Gottman; psychology is a small world) decided to try to document this effect. They gathered a group of volunteers and hooked them up to monitors measuring their heart rate and body temperature—the physiological signals of such emotions as anger, sadness, and fear. Half of the volunteers were told to try to remember and relive a particularly stressful experience. The other half were simply shown how to create, on their faces, the expressions that corresponded to stressful emotions, such as anger, sadness, and fear. The second group, the people who were acting, showed the same physiological responses, the same heightened heart rate and body temperature, as the first group.
A few years later, a German team of psychologists conducted a similar study. They had a group of subjects look at cartoons, either while holding a pen between their lips—an action that made it impossible to contract either of the two major smiling muscles…—or while holding a pen clenched between their teeth, which had the opposite effect and forced them to smile. The people with the pen between their teeth found the cartoons much funnier. These findings may be hard to believe, because we take it as a given that first we experience an emotion, and then we may—or may not—express that emotion on our face. We think of the face as the residue of emotion. What this research showed, though, is that the process works in the opposite direction as well. Emotion can also start on the face. The face is not a secondary billboard for our internal feelings. It is an equal partner in the emotional process.