While a simple smile may involve contracting the muscles around the corners of your lips, a Duchenne smile usually extends to your eyes and causes wrinkles in the skin around them. A Duchenne smile is usually thought of as a genuine, joyful expression, but this isn’t always necessarily the case. You can use it as a guide for when someone may not be genuinely smiling, though, at least in some circumstances. Overall, smiling can be quite complicated, varying between cultures and individuals. Learning how to read and recognize certain smiles may help you better navigate social interactions and clearly communicate your own emotions, too. 

The History Of The Duchenne Smile

The Duchenne smile is named for the French neurologist Guillaume Duchenne, who theorized in the mid-1800s that there are two very different kinds of smiles.

Duchenne smiles flex the muscles at the side of your mouth and the muscle that lifts the cheeks and creates wrinkles around the eyes. This is a fact Duchenne noted, thus giving his name to these particular types of expressions. 

Duchenne believed that a smile that engages the eyes is associated with genuine positive emotions. In modern terms, a Duchenne smile has also been called “smiling with the eyes” or “smizing.”

However, some modern scientists have questioned Guillaume Duchenne’s methods and findings. If his name sounds familiar, it’s likely not just because he's famous for theorizing about our grins. He was also the father of electrotherapy. As he studied smiles, he attached electrodes to his patients' faces and shocked their muscles into contracting.

As you might guess, this system was very painful, so at first, Duchenne was only able to test his methods on the heads of decapitated French revolutionaries. Eventually, however, he met a man at a Paris hospital with severe facial insensitivity. Almost all of Duchenne's experiments were conducted on this man, using electricity to freeze his face into smiles.

Modern science has discovered that a smile can mean many things, and not all are pleasant.

There Are 19 Different Types Of Smiles

More recent studies have expanded on Duchenne's idea of just two smiles and have identified almost twenty different kinds of smiles.

For example, one type of smile is called the "fear smile." In chimpanzees, this smile is used when nervous or interacting with another chimp of a higher status. Studies have shown that human men also smile more when around someone they perceive to be of higher status. Likewise, when babies smile, it might mean that they are happy, or it may mean they’re under stress .

Another type of smile is paradoxically called the "miserable smile." This is a smile that can be used to mask deep pain. These smiles may be common among those living with depression and similar long-term mental illnesses.

Something called a "qualifier smile" can be used when delivering bad news. It's a kind of apology, a sweet, sad smile that says, "I'm sorry I have to tell you this." It can be especially common in customer service or among people who don't know each other very well.

Another ubiquitous smile can be the "flirtatious smile." The famous Mona Lisa painting is the most famous for its subtle, flirtatious smile.

What Does A Duchenne Smile Mean?

It is commonly believed that a Duchenne smile is a "genuine" smile. A non-Duchenne smile that doesn't employ the eyes, on the contrary, may very well be disingenuous.

There are many different types of smiles, and people can also fake smiles. A generic smile that involves merely moving the corners of the mouth could mean many things. Generally, human smiles can express joy or acceptance, but some cultures use smiles to show embarrassment or confusion. However, a genuine Duchenne smile is typically a smile of pure enjoyment.

However, an exaggerated Duchenne-type smile may also indicate that a person is lying. A study on smiling published by researchers at the University of Rochester, New York, showed the difference between a fake Duchenne-type smile and a real one. The researchers developed a program that used artificial intelligence to analyze millions of frames from interview tapes at airports with immigration services.

The program discovered that laypeople often used a big, fake smile. Honest people often contract the muscles around the eyes and smile with their eyes without using their mouths.

Scientists still wonder how much facial expressions are innate and how much they are learned from our culture and society. But in 2009, a team of scientists from San Francisco State University discovered in 4,800 photos that people produced the same or similar facial expressions, even if they have been blind since birth.

The Difference Between Real Smiles And Fake Smiles

The primary difference between Duchenne and non-Duchenne smiles may be in the eyes. A genuine Duchenne smile usually involves a crinkling of the corners at the edge of the eyes. A non-Duchenne smile may be focused predominantly on the muscles around the mouth.

Non-Duchenne smiles are also sometimes referred to as "Pan Am smiles." This type of smile might over-engage the mouth muscles while failing to include the eyes.

Can you fake a Duchenne smile? If it’s possible to contract the skin around your eyes, it may be possible to let a smile reach them intentionally. If you squint and smile with your mouth, it may appear as if you successfully produced a Duchenne smile.

There may be nothing intrinsically genuine about a Duchenne smile. But often, people can pick up on the subtle differences between genuine Duchenne smiles and false Duchenne smiles.

Whether conscious or not, people are often very good at picking up on differences in facial expressions. A smile of enjoyment usually engages the eyes, but subtly. A fake Duchenne smile can often be over-zealous and contracts the eyes too much, indicating this is not a smile of enjoyment but rather a fake smile.

Cultural Differences With Smiling

In most cultures, smiling is seen as a demonstration of positive emotion. For example, in the United States, smiling can be heavily encouraged in photos, customer service spheres, and even as a simple greeting. However, too much smiling might be equated with dishonesty or shallowness. If someone is constantly smiling, people may be reluctant to trust them in many cultures, as it comes across as disingenuous.

In some parts of Asia, a smile can signify embarrassment or emotional pain. A polite non-Duchenne smile can be similar to a wave or a friendly greeting in many cultures, while smiles are generally reserved for loved ones in other places.

Duchenne smiling is typically not used as a polite greeting or cultural norm. Instead, a Duchenne smile is often a genuine expression of happiness, and it can be difficult to fake. However, even the Duchenne smile may be subject to these differences in interpretation from different people and different cultures.

Learn More About Communication

Information about psychology and tips for better understanding people can be found through the support of a mental health professional like a therapist. Even if you don’t live with a mental illness like depression, having a space to ask questions and learn more about the world around you can be highly beneficial.  

Online counseling can be perfect for the curious learner because it may be significantly more affordable, and it can also be available from the comfort of your own home.

Research suggests that online therapy can successfully treat many mental health disorders, including depression, anxiety, panic disorder, and more. No matter your mental health concerns or questions, it’s likely that an online therapist can help provide some guidance and support.

Takeaway

The Duchenne smile refers to a smile that engages both the eyes and the mouth, and it's traditionally seen as a more genuine smile. Still, modern science reveals that the Duchenne smile can also be faked, or it could mean that someone is lying. So, there may be no easy, foolproof way to spot the difference between a fake smile and a real one. The best way to understand a smile may be to pay attention to context and communicate your emotions vocally.