The Plasticity of the Human Face

15 Oct 2007 // science

The study of emotions is one of the last frontiers of science, probably because scientists, being über-rationalists by nature, are innately afraid of such wet and sticky topics such as joy and fear and hot desire.

And the gateway to the emotion is undoubtedly the human face. No less an authority than Darwin first posited this in the seminal "The Expression of the Emotions in Man and Animals." And muscle by facial muscle, the mysteries of the face are slowly being unravelled, although we will probably never know what exactly the Mona Lisa was feeling in front of Leonardo da Vinci.

The study of the emotional expressiveness of the human face has suffered over the earlier part of the 20th century, when the dominant view was that facial expressions are socially determined. A Japanese smile does not mean the same as an English smile.

Today, the poster boy of the study of the human face is UCSF professor, Paul Ekman. Ironically, Ekman started out as a firm believer in the social malleability of the human face, but over the course of a career spanning 40 years, Ekman has come to believe that core human emotions are universal. Ekman has returned to Darwin.

The human face is a plastic broadcaster of the signals of emotions. It is hardwired into your genes and constrained by the shape and anatomy of the human head. Ekman has painstakingly mapped out the cartography of the human face.

There are 43 facial motions, and every permutation thereof constitutes a possible emotion – there are thousands of possible facial expressions.

One important distinction that Paul Ekman has made is that emotions should be distinguished from moods. Emotions are states, instantaneous reactions that signal how a person is primed to act, right now. Moods, such as depression, and happiness, are more long term dispositions. Emotions are bounded by moods. Emotions are states that flash across a face depending on what is happening in the world at this very moment. Although most facial expressions are dependent on the society – the key ones are innate.

So what are the innate human emotions? They are sadness/agony, disgust, anger, joy, surprise and fear. These emotions are universal, and they are recognized unfailingly from tribesmen in Papua New Guinea to academic scientists in San Francisco.

Emotions are involuntary, and there is a very good evolutionary reason for that. They allow cooperation between individuals. The general infallibility of emotions allows us to trust the facial signals of others, and glean what they are feeling. And inside our head, there are neurons that fire automatically on seeing the emotions of other – we have no choice but to respond to the emotions of others. Sadness begets sadness, anger begets fear. Emotions are based on very old neurological circuits – they operate in animals as well.

Nevertheless, the facial muscles are in the end, muscles. Through practice, Ekman shows we can improve our control over these largely involuntary muscles. But overriding their involuntary nature was designed to be difficult. The classic example is the fake smile. It seems fake because very few people can control the crinkling around the eyes in a genuine smile.

Of course, there are people who have the gift of consciously controlling their facial muscles. We call them actors. Sometimes we pay them shitloads to fake emotions convincingly.

The subtlety is not only in accurately activating the correct facial expressions for the basic emotions, but in the ability to display all the other emotions.

Whilst the basic emotions are universal, there are a whole range of secondary emotions that are not quite universal. A gifted actor can wrinkle these out, thus adding color and nuance to a role. Identifying these other emotions is exceedingly difficult. In the Method school of acting, it is assumed that the finer nuances cannot be done by study, they must be summoned from life experience. De Niro famously drove multiple 12 hour shifts in a taxi to prepare for Taxi Driver. Presumably, in those long and lonely shifts, De Niro came across situations that brought out these rare and unusual facial expressions that only taxi drivers experience that were later captured on 35mm.

If you want to immerse yourself in the scientific catalogue of human expressions, you would do well to study the books of Paul Ekman, for instance "Emotions Revealed", but be prepared, they are heavy going, and not the most elegant examples of English prose.

Still, the most interesting thing that I got from reading Paul Ekman was that Ekman proposes that there are a handful of emotions that were near universal but do not have English names.

One is from the Italian: fiero, the emotion of achieving a difficult task. It is in the pumping of fists that you see when Lleyton Hewitt wins a point. It is in the arms thrown to the exalted heavens when David Beckham scored that free kick against Greece. Another is from the yiddish: nanches – the pleasure at watching your children succeed. And seeing how his system of facial expressions have grown to become a useful tool, even for police work in the FBI, Ekman ought to be feeling very nanches indeed.