A smile is an essential facial expression that reveals a person’s emotional state, usually one of joy and happiness. While this is true, research has shown that there are different kinds of smiles, from those that happen in moments when the bearer is not truly happy to those that are forced to conceal a contrary emotion. The Duchenne smile, on the other hand, is a smile that is born out of happiness. Thus, it is the true expression of an individual’s joyous state.

The Duchenne smile was first observed by a French neurologist, Duchenne de Boulogne, who studied the muscles and muscle groups that perform different kinds of facial expressions.

During his study, Duchenne stimulated a primary muscle (Zygomaticus major) that is used for smiling. He discovered that his subject produced a large smile but did not look happy. Then he told the subject a joke and then observed that the face engaged a second muscle (Orbicularis oculi) to produce a much happier smile.

The zygomaticus major is a muscle found on both sides of the mouth. It moves the mouth upwards and sideways during facial movements such as smiling. On the other hand, the orbicularis oculi is a muscle found around the upper and lower eyelid. Its primary function is to help close the eyelids, which happens when the muscles contract.

Unlike the Duchenne smile, non-Duchenne smiles take place when the zygomaticus major is activated. The Duchenne smile engages both the zygomaticus major and the orbicularis oculi muscles, which researchers say is an indication of enjoyment and happiness.

Researchers believe that it is very difficult to contract the orbicularis oculi muscle voluntarily, thus making its contraction a good indicator of true enjoyment.

Why is the Duchenne smile important?

For a Duchenne smile to occur, there must be a simultaneous action between the brain and the respective facial muscles. This occurrence helps psychologists gain a deeper understanding of the connection between the mind and the body.

It is also essential to understand that a smile is a translation of positive emotion, in this case, happiness, which has a positive emotional and psychological effect. Research shows that having a genuine smile can help alleviate emotional burden and also reduce depression.

The Duchenne smile has also proven to be contagious, which is why when we see someone with a genuine smile, it creates an urge in us to smile. As a result, a genuine smile can increase a person’s sociability and how much people trust them. Several studies also show that people who smile more are seen as more attractive than people who do not smile. Thus, the attractiveness that comes from having a genuine smile increases an individual’s social possibilities.

The Duchenne smile can also be used as a persuasive tool. A smile, when perceived as genuine, makes it easier to persuade someone. The persuasive possibility of the smile can range from convincing someone that something is true to convincing them to buy something from you. For example, a study showed that when celebrities flashed a Duchenne smile during a product endorsement, the product was perceived in a more positive light.

With the benefits of the Duchenne smile, one is forced to ask the question, can the Duchenne smile be faked? While earlier scientists believe that the orbicularis oculi muscle is not within voluntary control, recent studies show that the Duchenne smile can be faked.  

The idea of faking a Duchenne smile benefits from the facial feedback hypothesis. This hypothesis posits that our facial expressions directly affect our emotional experience. The hypothesis has the support of research that shows that when we are able to fake a smile, it creates a feeling of happiness.

The Duchenne smile is a powerful facial expression. Even when faked, the Duchenne smile retains its ability to influence both our emotions and the emotions of others. Therefore, I think it is worth paying attention to. So, the next time you see someone smile, try to determine if it’s Duchenne or not.