When You Smile to the World, the World Smiles Back

I have been in Paris for two weeks now, and I am still marveling at the sights and beauty of this new world around me. For anyone who doesn’t know, this is actually my first time out of America, so I have never really experienced culture shock like I have here in Paris. There are so many differences I have noticed, from restaurants only giving room temperature tap water to drink for free, to having to pay for bags in the grocery store, to the language barrier I deal with everyday.

If you know me, you know I am ALWAYS smiling. No matter what I’m doing, or who I’m talking to, 99% of the time I have a huge smile on my face. When I first got to France, we were staying at the Ibis Hotel near the Accent Study Abroad center in the heart of Paris.

As my friends and I were roaming the area, I kept making awkward eye contact with the French people walking, and I noticed something super strange: NONE OF THEM SMILED. It’s regular for me to make eye contact with someone, and even if I do not know them, I smile because where I’m from, that is the polite thing to do. However, I smiled at each and every one of these people, and each of them stared back at me with a blank expression. I honestly thought it was so rude. I immediately turned to my friends and said, “Did you guys notice that nobody here smiles? Isn’t that like human nature to smile at people? French people are so rude.” Even my friends thought that smiling at strangers was just the way the world worked, and even they were confused by this lack of expression from the Parisians. Once I got home, I googled “Why don’t French people smile?” (also if you know me, you know I google absolutely everything). I found a very interesting blog post about how that is just a major cultural difference between Americans and the French. Apparently, French people reserve their smiles for people they actually know. In fact, that actually find it strange when strangers smile at them, and they think it means they are making fun of them (Paridis 2013).

A photo I took walking down the street. Normally, it is pretty normal for people to not smile when they are just walking, but I made eye contact with two people after this photo and smiled, and neither of them smiled back.

After reading this blog, I began wondering how these cultural differences came about. I started questioning if it was actually weird that Americans just smile at people we don’t even know, or are we just extremely friendly people? As a personal preference, I love smiling. I don’t understand why anyone would not want to smile at people whether they know them or not. Smiling is a universal sign of kindness, so why not share it with the world?

As I was searching this subject (on google of course), I came across a neuroscience research article that proved that smiling can affect the way our brains process other peoples’ emotions (Sel et al., 2015). The study, interestingly enough, was conducted in France in 2015. There were 25 right-handed men and women with normal vision who participated in this study. For the experiment, each participant was shown a set of 90 pictures depicting happy and neutral emotions. In two separate blocks, they asked participants to adopt either a happy or a neutral facial expression during a judgment task of the emotional intensity of the images presented. Previous research shows that intentionally putting on an emotional facial expression is directly correlated with increased activity in the emotional brain network (Kuhn et al., 2011). The participants were also receiving an EEG (a test to detect electrical activity in your brain) while they were performing the judgment task. An N170 is a component of the EEG that shows the neural processing of faces. Literature suggests that the N170/vertex positive potential (VPP) complex is the brain activity shown when people are observing others’ facial features.

Fig. 1 (A) Experimental manipulations: self-neutral block, participants were asked to maintain a neutral expression and relax their face; self-happy block, participants were instructed to hold a happy expression by biting on a pen horizontally with the teeth. Control manipulation: self-control block, participants were asked to purse their lips in order to hold a pen with their lips only. (B) Timeline of the stimuli presentation. (Sel, 2015)

By performing the experiment this way, researchers were able to determine the effect of the participants emotional expression on the brain mechanisms underlying visual processing for the observed facial expressions. If the face processing was independent of the participants emotional expression, then the VEPs (visual evoked potential; brain activity caused by a visual signal which is seen on the EEG) of observing other’s happy and neutral faces wouldn’t be affected by their own facial expressions.

However, as the researchers hypothesized, the results showed that the participants’ facial expression of happiness significantly altered the N170/VPP of when they observed other neutral faces compared to when they observed the neutral face while also having their own neutral expression (evidenced in the difference between the red and green lines in figure 2A below). The results suggest that when people are smiling, they actually observe other neutral faces similarly to the way they view a happy face.

Fig. 2 (A) Grand average VEPs when observing happy faces (green: self-happy condition; red: self-neutral condition) and neutral faces (blue: self-happy condition; black: self-neutral condition). (B) Selected electrodes included in the ANOVA (Sel, 2015)

The results support the hypothesis that intentionally adopting a certain facial expression can change the subjective feelings corresponding to that emotion, which then influences perception of other’s facial expressions. They show for the first time that a person’s happy expression acts as an influence on visual processing, modulating neural activity when one observes neutral faces as compared with happy faces.

One strength of this study is that after the study, they went back and added another control to further validate their conclusions. Based on the way the study was conducted, it can be argued that the effects of self-happy expression on visual processing of others’ facial emotions could just be based on the contraction of facial muscles in general, rather than specifically smiling. To rule out this possibility, the researchers added a control in which the participants had to clench their mouths in a way that prevents smiling, but still contracts facial muscles. The results of the control were the same as they were for the self-neutral expression, which further proves that the effects shown in the VEPs to neutral faces are specific to the participants smile. This reassures that there is a direct contribution of one’s own facial expression of happiness to the way that person visually processes others’ faces.

A weakness I found in this study is that when choosing participants, it is not stated if they ruled out people with certain mood disorders, such as bipolar disorder or manic depression, that could automatically influence how they perceived the others’ emotional expressions. I think that going forward, it would be interesting to specifically test how the effect of smiling can work in people with mood disorders.

As for me, I am completely happy with the results of the experiment. It just goes to show that really, if you smile at the world, the world will smile back at you (at least you will perceive it that way).

Until next time,

Keep on smiling!



Kuhn S, Muller BC, Van Der Leij A, Dijksterhuis A, Brass M, Van Baaren RB (2011) Neural correlates of emotional synchrony. Social Cognitive and Affective Neuroscience 6: 368–74.

Paradis V (2013). Don’t Smile!. French Truly. Web.

Sel A, Calvo-Merino B, Tuettenberg S, Forster B (2015) When you smile, the world smiles at you: ERP evidence for self-expression effects on face processing. Social Cognitive and Affective Neuroscience 10.10: 1316-322.


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