Smiling is good for your physical and mental health, but what about a fake smile?

Produced by | Science Popularization China

Author | Duck Brother Science Popularization

Producer | China Science Expo

When we see someone smiling happily, we would say that he "smiles like a naive child." This does not mean that children have no worries, but that this kind of smile from the heart often makes people feel warm and pure.

This natural smile caused by happy emotions has many benefits. It can not only adjust your mentality and convey friendliness, but also show your confidence to others, exude charm and fascinate everyone.

But in addition to real smiles, we often see fake smiles - such as the awkward smile you slowly squeeze out when facing the stern gaze of the teacher when you are late for class. Compared with real smiles, fake smiles are not from the heart, and the expression seems deliberately hypocritical.

Image source: GIPHY official website

So what is the difference between a fake smile and a real smile? Can a fake smile trick the brain into producing positive effects? Or is it because a fake smile is so deliberate that it causes adverse physiological reactions?

01

True smile = Duchenne smile

To understand fake smiles, we first need to understand what a real smile is. Through the different combinations, contractions and contortions of the 42 muscles in our face, the face we present to the world is constantly changing. Humans can produce thousands of different facial expressions - including 19 different types of smiles.

However, according to research by American psychologist Paul Ekman, only one of these is a "real" smile, the Duchenne smile.

Duchenne smile | Image source: wikipedia- Eric McGregor

The Duchenne smile was discovered by French anatomist Duchenne in 1862, but it was not taken seriously until the 1950s and 1960s.

Through research, Du Xing found that a "real" smile mainly involves two facial muscles, namely the zygomatic major muscle connected to the corners of the mouth and the orbicularis oculi muscle around the eye socket. The contraction of the former can lift the corners of the mouth, and the latter can pull the apple muscles upward and make the eyes appear more curved. At the same time, some people will have smile lines at the corners of their eyes, or their eye bags will become more obvious.

02

You're exposed, you're smirking

In contrast, a fake smile appears "slightly calmer." The lip corners of a fake smile move in the same way as a real smile, but without the changes caused by the muscles around the eyes. If you cover the lower part of the face when you're smiling, you'll notice that the eyes are dull and the eyebrows don't arch.

Duchenne smile (left) and non-Duchenne smile (right) Image source: Reference [3]

Duchenne confirmed this in his previous research. He used electric shocks to stimulate the zygomatic major muscle of the experimental subject, as shown on the left side of the picture below. This made the subject's mouth twitch, but the expression of his eyes was weird; then he told the subject some happy things, which made him laugh spontaneously. The picture on the right shows the subject's smile from the heart.

The same subject's smile on the right is obviously more natural and happier, just like when you receive the news that your final exam is cancelled or your vacation is extended by ten days. So, a real smile will cause the orbicularis oculi muscle to move, which will cause the eyes to close slightly.

Fake smile (left) and real smile (right) Image credit: G.-B. Duchenne de Boulogn

03

Real Smile vs Fake Smile: Can You Really Tell the Difference?

With the above knowledge, can we conclude that as long as the eyes are not closed at all, it is definitely a fake smile? In fact, if you deliberately make an exaggerated smile, it will also cause the corners of the eyes to close; and a real smile, if it is just a slight smile, will not make the eye sockets narrow.

Therefore, in order to tell whether the person opposite you is smiling genuinely or fakely, you have to look for more subtle details, such as slightly lowered eyebrows, the skin between the eyebrows, the state of the upper eyelids, etc.

Image source: Reference [4]

You may ask, if someone can actively control these facial muscles, wouldn't it be impossible to tell whether a smile is real or fake? In theory, yes, but according to Ekman's research, almost no one can actively contract the orbicularis oculi, which is part of the muscles that are difficult to actively contract.

Human facial muscles and the location of the orbicularis oculi muscle | Image source: openstax.org

The orbicularis oculi muscle consists of two parts: an inner ring that tightens the eyelid and the skin under it, and an outer ring that surrounds the eye socket, pulling down the eyebrow and the skin under it and lifting the skin under the eye and raising the cheek.

Strictly speaking, the inner circle muscles that tighten the eyelids are controllable by everyone, and without this action we cannot expose a fake smile, but the outer circle of the orbicularis oculi muscle is difficult to control.

It has long been believed that being able to pull off a Duchenne smile in a photo is a natural gift, and that faking a smile well may be a skill that varies from person to person. But research in recent years seems to disprove that view: With practice, you can make a fake smile look good and genuine (at least it looks that way).

In the study of simulated Duchenne smiles, even when participants heard unhappy news, they were still able to smile 24% of the time (compared to 31% of those who smiled genuinely). And when the researchers asked them to imitate a Duchenne smile, 71% of them succeeded.

In addition, many actors with excellent acting skills seem to feel genuine happiness when they laugh. They may be among the very few people who can control the outer orbicularis oculi muscle. Of course, it may also be that recalling triggers memories containing pleasant emotions, thus producing a real expression.

04

It’s okay to fake a smile, but don’t drink too much

As we all know, "a smile makes you look ten years younger" and keeping a smile is good for your health. When we laugh, our facial muscles react, driving our nerves to produce corresponding hormones and triggering a series of stress-relieving reactions. So when we fake a smile, will it have the same effect?

The answer is yes. Although genuine smiles have the strongest effect, there is evidence that even fake smiles can have a similar effect. According to research from Delft University of Technology in the Netherlands, fake smiles achieve this through a phenomenon called the Facial Feedback Hypothesis (FFH): artificially displaying a certain facial expression can lead to the generation or enhancement of the corresponding emotional experience.

Image source: Veer Gallery

Fake smiles can reduce stress and bring about the physiological effect of "making the fake look real", but long-term fake smiles are not good for physical and mental health. For work or social needs, many people have to fake smile for a long time and always maintain a "standard smile" for business purposes.

In the long run, this professional smile suppresses a person's true feelings and makes the "smile" a burden. Over time, it may even develop into depression. It is often manifested as feeling very anxious and depressed deep in the heart, but appearing calm and smiling on the outside.

Image source: pixabay

A genuine smile makes people feel refreshed, like a spring breeze, but this does not mean that fake smiles are useless. Fake smiles are a social etiquette and can also bring positive reactions similar to real smiles.

It's just that fake smile is like medicine, it should be used only when necessary, and often forcing a fake smile will only make you feel tired. In short, we don't need to bear the burden of fake smiles. The most important thing is to smile sincerely and be a "heartless person"!

References

[1] Facial expressions and behavioral consistency: how to identify fake smiles?
http://jysh.people.cn/n1/2019/0918/c404390-31358734.html

[2] Duchenne de Boulogne. https://en.wikipedia.org/wiki/Duchenne_de_Boulogne

[3] Sacco DF, Brown M, Lustgraaf CJN, et al. Women's dangerous world beliefs predict more accurate discrimination of affiliative facial cues[J]. Evolutionary Behavioral Sciences, 2017, 11(4): 309.

[4] Vandeventer J, Patterson E. Differentiating Duchenne from non-Duchenne smiles using active appearance models[C]//2012 IEEE Fifth International Conference on Biometrics: Theory, Applications and Systems (BTAS). IEEE, 2012: 319-324.

[5] Paul Ekman. https://zh.wikipedia.org/zh-hans/%E4%BF%9D%E7%BD%97%C2%B7%E8%89%BE%E5%85%8B%E6%9B%BC

[6] Smiling with Your Eyes: What Exactly Is a Duchenne Smile? https://www.healthline.com/health/duchenne-smile

[7] Fake Smile or Genuine Smile? The importance of the Duchenne smile. https://www.paulekman.com/blog/fake-smile-or-genuine-smile/

[8] Duchenne Smile, A genuine smile that involves the muscles around the eyes. https://www.newscientist.com/definition/duchenne-smile/

[9] How to spot a fake smile? 3 scientific ways to help you see through your friends’ acting skills
https://www.bilibili.com/read/cv1709480/

[10] Why do you stop smiling when taking photos? Why do smiles in photos always look forced?
https://mp.weixin.qq.com/s/OnH78RZh6e7CZRHc634eJQ

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