Charles Darwin wrote about expression in his book The Expression of the Emotions in Man and Animals. He derived some of his evidence from Guillaume Duchenne, who was interested in the physiology of emotion. Duchenne studied the muscle movements of the face using methods that we would consider highly unethical today– administering electrical shocks. Although they weren’t the first to study expression or suggest universality, the work of Duchenne and Darwin was significant and led to extensive study a century later. You can read more about the work of Duchenne, Darwin and the history of expression on the my alCOM.y website. 

Malcom Gladwell offers an interesting account of Tomkins' remarkable ability to read faces, as well as interactions between Tomkins and Ekman in his book Blink. An excerpt can be read here.

Some researchers have studied facial expression in blind people, hypothesizing that if expressions are universal, they would be displayed in the same way in both sighted and congenitally blind people. One such study, by Matsumoto and Willingham, examined culturally diverse, blind and sighted Judo athletes at the 2004 Athens Paralympic Games. They examined spontaneous expressions displayed immediately after winning or losing their match, when receiving their medal and when posing on the podium. They found that both blind and sighted athletes displayed expressions of emotion in the same way– and consistent with emotions likely to be evoked by winning or losing their match. This suggests that the display of expressions could not be a learned behavior.

In the 21st Century, many researchers agree that there are seven universal expressions (anger, fear, disgust, surprise, happiness, sadness and contempt), but could there be more? In 2016, researchers from Ohio State University discovered a potential eighth universal expression: "the not face." With a furrowed brow and lips firmly pressed together, it communicates negative moral judgement–– disapproval or disagreement.

Another interesting discovery is the microexpression, which was studied by Haggard and Isaacs in 1966. The microexpression is a fleeting expression which occurs within a fraction of a second. These have been linked to deception detection since they reveal a concealed or repressed emotion. You can read more about microexpressions and emotion spotting here.

Ekman and Friesen developed a coding system– Facial Action Coding System (FACS)– based on the work of Carl-Herman Hjortsjö. Researchers use this system to code individual muscle movements (action units) produced in the face, while studying the expression of emotion. More recently, researchers have created facial action coding systems for animals including cats, dogs, sheep, horses, orangutans, gibbons, macaques and chimpanzees. In some instances, these have been created to assess pain levels. Although less is known about expressions of emotion in animals, they are thought to be reflective of emotional processes, with evidence suggesting some expressions can be intentionally displayed, functioning as a deliberate signal to others. Interested in learning more about animal behavior? Watch Inside the Minds of Animals by Bryan B Rasmussen. Or Moral Behaviour in Animals by Frans de Waal.

The development of a Facial Action Coding System and other technologies that recognize emotion and automate coding, in both humans and animals, pave the way for future discovery and understanding. One use of this kind of technology is to diagnose pain in those that can’t communicate verbally– apps are in use, for both human and animal pain assessment.

Can machines read your emotions? Find out in Kostas Karpouzis TED-Ed animation.

Supported by the Dalai Lama, Ekman created the Altas of Emotion, an interactive tool that helps to build an extensive vocabulary of emotions, helping people to discover how they are feeling and why, which is the first step in gaining emotional control.

There’s some evidence that our expressions serve another purpose–to influence our own emotional state. This is called facial feedback hypothesis. So, when we express an emotion, we start to feel that emotion, and that’s why emotions are so contagious. While interacting with others, our mirror neurons fire repeatedly for a fraction of a second each time. Eventually we start to feel their emotion. This is the basis for empathy and can improve group fitness. This short video animation explains this concept. The most compelling evidence for facial feedback hypothesis comes from studies using Botox injections, which target and paralyze specific muscles. Researchers have found that by targeting the muscles in the nose, for example, feelings of disgust are suppressed. Potentially this could reduce symptoms of obsessive compulsive disorder. On the downside, this would mean that by targeting the upper cheek muscles with Botox, feelings of happiness would also be suppressed.

Next Section »