Why Psychologists Study The Duchenne Smile, And What It Means For You

By Danni Peck |Updated March 2, 2022
CheckedMedically Reviewed By Christy Booze, LCSW

When we speak of smiles, our first thought may be a smile of pure happiness. There are other smiles, too, though. There's the smile of fear, the smile of embarrassment, the smile of anger. These smiles have their own distinct physical characteristics. The Duchenne smile is a very unique type of smile that psychologists have been studying for over a century. The Duchenne smile is the smile that continues to fascinate researchers and the public alike.

What Is The Duchenne Smile?

The Duchenne smile is named after Guillaume Duchenne, a French anatomist who studied many different expressions of emotion, focusing on the smile of pure enjoyment. He identified thefacial movements that make this smile different from other types of smiles.

Duchenne Smile Definition

The exact definition of the Duchenne smile is a bit technical, but we'll break it down for you. A Duchenne smile is a natural smile of enjoyment, made by contracting the zygomatic major muscle and the orbicularis oculi muscle. It’s often quite involuntary, and experienced during times of genuine happiness or enjoyment.

What Does The Duchenne Smile Look Like?

When you see someone displaying a Duchenne smile, you naturally feel positive emotions for the person smiling. The smile is distinctive, with the mouth turning up (the zygomatic major muscle), the cheeks lifting, and the eye sockets crinkling to create crow's feet (the orbicularis oculi).

What Makes The Duchenne Smile So Special?

The Duchenne smile is different from a non-Duchenne smile in several ways. First, the Duchenne smile uses both the zygomatic major and the orbicularis oculi. A non-Duchenne smile doesn't reach the eyes but resides only on the lips and possibly the cheeks.

Second, the Duchenne smile is considered a natural smile of enjoyment. In the past, the consensus among researchers was that a true Duchenne smile couldn't be faked. More recent research calls that into question. Now, researchers spend more time trying to find out how we benefit from and how we can produce the Duchenne smile.

Early Study Of Smiles

Artists have been captivated by smiles throughout history. No smile is quite like the smile of the Sphynx or the Mona Lisa smile. Smiles have been a subject of scientific interest for at least a century. To most researchers, the Duchenne smile is the most interesting, partly because of the question about whether we can produce it on command.This subject has drawn interest from some of the most famous scientists in the world.


Guillaume Duchenne had an unusual way of conducting research. Using people at a psychological hospital as subjects, Duchenne produced various expressions by stimulating facial muscles with electrical current. The procedure was said to be extremely painful. In fact, Duchenne sometimes used the recently severed heads of criminals who had died by capital punishment to relieve the people in the hospital from enduring the study.

Eventually, he published a book explaining what he found through his studies. The book was called 'Macanisme de la PhysionomieHumaine,' published in French in 1862. In the book, Duchenne describes and explains his research on the smile that bears his name. Duchenne was the first to identify the smile that included both the zygomatic major and the orbicularis oculi and signified pure joy.


During the same historical period when Duchenne did his work, Charles Darwin studied facial expressions and their role in the survival and evolution of the human species. In 1872, Darwin published a book called, 'Expression of the Emotions in Man and Animals,' which dealt with the types of expressions we use, what they look like, and what purposes they serve for communication and cohesiveness of groups.

Diagrams within this book show the muscles responsible for making our facial expressions. Darwin goes on to discuss his interpretations of expressions like the smile of joy, which roughly correlates to the Duchenne smile. In fact, within this text, Darwin mentions Duchenne and gives him credit for successfully explaining how those muscles create that distinct smile.

Carney Landis

A psychology student at theUniversity of Minnesota, Carney Landis conducted some pretty bizarre and overall unethical experiments to study human facial expressions. He put his subjects in unexpected situations and photographed them. Some of the situations included putting their hand in what turned out to be a bucket of frogs, watching porn, smelling ammonia, and even being asked to decapitate rats (which 1/3 of participants did, while the other 2/3 who refused were made to watch as Landis did it for them).

Landis's original question was whetherfeelings about the situation caused the facial expression, and if all people share a common expression when experiencing things like joy, fear, etc. His study was published in 1924, in the Journal of Comparative Psychology, and quickly caught on within the field of psychological research.

A lingering problem with Landis' study is that he failed to recognize the subtleties of how different facial expressions can show very different emotions. He didn't recognize the Duchenne smile and said that smiles were common in any situation. He saw no relation between the smile and a sense of enjoyment or satisfaction.

However, Landis did accomplish something positive and meaningful with his work. That is, he asked a question that would be the subject of study for the next 90+ years: Do emotions cause expressions, or is it the other way around?

Ekman And Friesen

Finally, in the 1970s, Paul Ekman and Wallace Friesen brought back the idea of the Duchenne smile. They also cataloged 3,000 facial expressions in their coding system called the Facial Action Coding System, which has been an extremely helpful tool for researchers studying the Duchenne smile and other expressions. The FACS shows photos of the expression, its description, and the facial muscles used to produce it. In their guide, you can see the action of the zygomatic major and the orbicularis oculi, although each is shown separately.

Psychologists' Goals For Studying The Duchenne Smile

So, why do psychological researchers study facial expressions, anyway? Sure, they're interesting, but what purpose can this serve? And, why study the Duchenne smile specifically? One thing you need to understand is that this smile involves action in both the brain and the muscles of the face, so learning about it helps psychologists understand the mind-body connection better.

The Duchenne smile also impacts the situation you're in at the moment, so there's a social aspect to it. Finally, the smile can be an indicator of emotion, a subject that's incredibly important to psychologists. Here are some of the specific reasons they study it.

To Understand Better How The Brain Processes Facial Expressions

When we see someone's facial expressions, how do we know what emotion they're expressing? Some neuroscientists recently asked this question. They took EEGs of people smiling to find out if their brains would process other people's emotions differently depending on their expressions.

The subjects were told to smile or hold a neutral face. Then, they were shown photos of people with neutral faces. When the subject smiled, their brains showed different processing than when they held a neutral face and viewed the photos. This study on smiling, published in 2015, didn't specifically address the Duchenne smile; however, it did show some interesting facts about facial expressions that might later be applied to the Duchenne smile.

To Test The Facial Feedback Hypothesis

The facial feedback hypothesis states that the way you move the muscles of your face can change your emotional feeling. This hypothesis has been tested in many studies, including a study by Robert Soussignan published in 2002. This research targeted Duchenne and non-Duchenne smiles specifically. When the subjects produced a Duchenne smile - fake though it was - they had a more pleasant and enjoyable experience, proving the facial feedback hypothesis as being right in this particular instance.

To Better Understand How The Smile And Thoughts Affect Each Other

Scientists don't just want to know the neurological components of the smile. They also want to know how our thoughts affect how we express ourselves and how our expressions change not just our emotions but also our conscious thoughts.

To Learn More About Human Emotion

A part of the reason psychologists study facial expressions is to understand our emotions better. Much of the work of a clinical psychologist or counselor is to help clients express and regulate their emotions. The more complete their understanding of these emotions, the better they can help their clients.

Not only do therapists need to understand emotions to help their client directly, but they also need to be able to identify emotions by noticing facial expressions as clues to inner states. This gives them the ability to understand the clients' reactions so they can respond appropriately.

To Find Out About Smiling And Child Development

Researchers have also studied the intersection of child development and facial expressions. One study by Ruiting Son, Harriet Oliver, and Malinda Carpenter investigated the stages of development of recognizing genuine Duchenne smiles. The study showed how the children responded to these smiles.

At age 3, children look more often at people showing the Duchenne smile than non-Duchenne smiles. By age 4, the children could verbally point out the 'real' (Duchenne) smiles and the 'fake' (non-Duchenne) smiles. At ages 4 and 5, the children expected the person with the Duchenne smile to be more friendly and helpful than the person with the non-Duchenne smile.

To Understand Differences

Psychologists look for both the similarities and the differences in human behavior across cultures and among individuals. Researchers studied the differences between countries (like the U.S.) where smiling is more acceptable and countries (like Russia) where smiling is discouraged.

In a multicultural study, people who smiled were considered more intelligent than others by people in countries where smiling is encouraged but less intelligent by people in countries where smiling was discouraged. These multi-cultural studies are important to help people of different cultures better understand and, ideally, get along with each other.

Individual differences in smiling have also been studied. For example, in a study by K.L. Schmidt and J.F. Cohn, some people showed partly non-Duchenne characteristics even though they were enjoying themselves.

To Find Out The Benefits Of The Duchenne Smile

One of the most important reasons to study Duchenne smiles is to find out how they can benefit us. Researchers are studying how this genuine smile can influence our mental and physical health, our social interactions, and even such things as marketing and persuasion.

To Find Out If The Duchenne Smile Can Be Faked

If the Duchenne smile is beneficial, the next question has to be: Can I intentionally choose to show a Duchenne smile? Recent research seems to indicate that some people can fake a Duchenne smile. If so, this has some interesting implications for psychology and research.

Decrease Depression

The Duchenne smile creates good feelings in an unexpected way. When you see someone using that facial expression, your lips naturally twitch into some version of a smile. Since past studies have shown that when you smile, hormones and endorphins are released that instantly improve mood, it stands to reason that seeing a happy face will boost your mood.

In a recent study, researchers Javier Elkin and Dr. ParashkevNachevshowed just that. They sent a photo of a happy face to subjects via smartphone. The people reported feeling better afterward; these results suggest that smiling may improve low moods.

Improve Personal And Social Relationships

Of course, if you feel better, you're going to feel more secure, connected, and overall at ease with both yourself and with others. This bleeds into your relationships, be they platonic or romantic. What's more, as research shows, you'll seem more attractive. If you're a woman, you'll also seem more trustworthy. People want to spend more time interacting with you. All of these factors can improve your personal and social relationships dramatically.

Be More Persuasive

The Duchenne smile, even when applied deliberately rather than involuntarily, makes it easier to persuade someone of something. You can use this fact not only to convince someone that something is true, but you can carry it further and convince them to buy from you. One study published in the Journal of Advertising Research showed that celebrities who flashed a Duchenne smile during endorsements for products were seen in a more positive light. This means that if you can produce a Duchenne smile, you'll  likely be able to influence others more easily.

Find More Enjoyment In Life

One of the most important parts of life is simply enjoyment. Our modern world doesn't always lend itself to pleasant experiences or letting go and just enjoying the moment. However, sporting a Duchenne smile can enhance your ability to feel pleasant, positive emotions. Simply put, it’s possible that you could enjoy your life more by smiling the Duchenne smile more often.

How To Smile The Duchenne Smile

If you can voluntarily produce a Duchenne smile as many researchers now believe is possible, how do you do so?

To create a Duchenne smile, start by thinking of something happy. Picture someone you love or remember a happy event. Some people prefer to think of something humorous. Sometimes, just changing the way you're thinking at the moment is enough to foster a Duchenne smile.

If not, try mirror practice. Think that happy thought as you look in a mirror. Then, try to smile, activating your lips, cheeks and eye socket muscles. When you see you've produced a genuine-looking smile, notice what muscles you're using. The more you practice, the better you'll get at producing it,and the more easily it will come in the future.

How Online Therapy Can Help

When smiling seems impossible, you may need some extra help to put a Duchenne smile back on your face, and that’s okay!You can talk to a therapist anytime you're ready. Licensed counselors are available at BetterHelp.com for online therapy at a time and place that's convenient for you. You can smile a big, beautiful Duchenne smile and learn to enjoy your life more than ever before!

Online therapy is an incredibly useful tool for a broad variety of people. If you’re struggling to smile, it might help to know that 70% of BetterHelp users experienced notably decreased depression symptoms, while 98% of all users across a wide range of conditions had significantly improved their conditions and mental health after treatment. What’s more, 78% of users classified as having “severe depression” prior to online treatment were no longer classified as such after 3 months of treatment, with 15% of them reducing down to mild, or low, depression.

It doesn’t matter whether your schedule is crazy and packed, leaving no room to drive to and sit in a session, or you live in a rural setting too far away to commute to sessions, or you just prefer virtual communication – BetterHelp is widely accessible. All you need is an internet connection to get started! After that, you can have sessions with a licensed therapist matched to you via phone, video chat, texting/instant messaging, live voice recording, or any combination therefore. Additionally, because there is no designated office to go to, online therapy is often a more affordable option than face-to-face therapy. Continue reading below for reviews of some of our therapists from people learning to find their true smile again.

“Karyn's perspective on my life and my experiences, particularly in my relationships, has opened my eyes to things I've never been able to see before in my own personality and behaviour. She challenges me! She affirms me! She laughs with me! When I cry, she talks me through it and lets it happen! It's been so helpful and wonderful to have an outside perspective on my feelings during a pandemic, especially. She's helping me become the best version of myself. :)”

“Such a beautiful person, caring and understanding. After my first session with her I felt like a weight was lifted off my shoulders. Talking to her is like talking to a very close relative or someone you have known your entire life. She got me to laugh and smile on a day I felt like ending it all. One of gods angels doing work here in the living is how I would describe her. God bless her heart and mind”

If you or someone you know are experiencing thoughts of suicide, reach out for help immediately. The National Suicide Prevention Lifeline can be reached 24 hours a day at 1-800-273-8255.

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