The Power of a Smile - Three Experiments

Thanks to several experiments on the power of the smile conducted in different parts of the world, we now know that it isn't enough to just smile. A smile must be sincere and reflect genuine feelings.
The Power of a Smile - Three Experiments

Last update: 17 June, 2020

Scientists say that only humans smile. However, some people perceive smiles in their pets or other animals. What’s for sure is that it’s a high impact expression, not only for the one who smiles but those who are smiled at. There have been several experiments on the power of a smile that sort of prove it; nearly all of them reached the same conclusion.

But you don’t have to take scientists’ word for it, as you can conduct your own experiments and draw your own conclusions. For example, ask someone for a favor by displaying a serious facial expression and then do the same but smiling this time. See if their response changes.

We all tend to trust people who smile. We have unconscious mechanisms that allow us to detect when someone smiles sincerely or not. When the gesture isn’t genuine, then a smile has the opposite effect and we distrust them instead. This is part of what the experiments on the power of a smile prove. Let’s discuss three of them.

1. The power of a smile – social glue

A woman laughing.

One of the most interesting experiments on the power of the smile was conducted by scientist Ron Gutman, a researcher on the subject. The findings of this investigation were published in Forbes magazine in an article called “The untapped power of smiling“.

Through this study, we learned something very interesting. The researchers placed a young monkey next to two people. One of them was smiling and the other one wasn’t. Amazingly, the animal approached the person who was smiling. The test was repeated several times and they obtained the same results every time. As you can probably guess, something similar occurs among humans.

The aforementioned article also reviews a study conducted at the University of Uppsala, in Sweden. It aimed to study the reactions of the people who displayed various facial expressions. The study concluded that people who smile tend to rub off their good disposition. So, in conclusion, “smiling is evolutionarily contagious”. Therefore, a smile helps bring people together and is a “social glue”.

2. A smile is memorable

A woman happily talking on the phone.

Another experiment on the power of a smile was conducted at Duke University in Durham. 50 volunteers were asked to interact with a woman from a “travel agency”. Some of them talked to a woman who remained serious, while the second group spoke to one that seemed sad. The third group talked with a woman who smiled.

In the end, everyone who interacted with the smiling woman said they were more attracted to the business in question. They also said they would definitely do business with her again. The same researchers established that the orbitofrontal cortex gets activated in the presence of a person who smiles. This is the area of ​​the brain related to gratification.

Similarly, they found that a smiling face generated greater remembrance, that we record a rewarding experience more clearly in our memory. In the same manner, we tend to be more open to requests made by people who smile.

3. Fake smiles don’t help

In 1980, German psychologist Fritz Strack,  a social psychologist at the University of Würzburg, conducted another experiment on the power of a smile. The results of his study became very popular in spite of his rather precarious methodology. He concluded at the time that if a person is sad and forces themselves to smile even if they don’t feel like smiling, their mood will improve.

However, when 17 other researchers from different parts of the world tried to replicate the Strack experiment, they obtained unclear results. This is why researcher Eric-Jan Wagenmakers, a psychology professor at the University of Amsterdam, decided to conduct a much deeper study to analyze the subject in more detail.

Furthermore, he conducted an investigation with 1,894 people and a highly rigorous method. In the end, Wagenmaker concluded that no scientific evidence backs that a forced smile improves a person’s mood. In fact, they detected no subjective change in those who faked a smile.

As you can see, smiles aren’t just facial expressions. They must be accompanied by a real feeling in order to be effective. Certainly, you can look for the kind of stimuli that’ll lead you to a smile and improve your mood.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.


  • Rulicki, S. (2013). Detective de sonrisas: curso avanzado de comunicación no verbal. Ediciones Granica.

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