I was looking for ideas on what to write about in my next blog and I realized that during my CAS class we were talking about how something as simple as smiling for a few seconds can change your whole attitude. I was curious to find out how.

How can a smile change your mood? 

I first found an article that described a study done by Robert Zajonc in which he had a group of individuals and he had some of them make vowel sounds that forced a smile and others made vowel sounds that forced a frown. His research found that smiles produced happy emotions much more than the emotions that the group making frown faces reported. These emotions were measured through a before and after questionnaire. Moreover, the study had huge impacts on this particular type of research because before Zajonc, there hadn’t been a mechanism linked to smiling and happiness. As it turns out, Zajonc was able to find a physiological link. This led to research about other emotions too, and studies showed connections between what your face does, and actual changes in mood, body temperature, and heart rate.

My attempt to explain the mechanism according to Zajonc:

Zajonc proposes that there are a lot veins leading into the face from the main brain vein (sorry about that rhyme…). It has been proposed that warmer temperatures produce negative emotions such as anger or stress, while cooler temperatures produce emotions like calm and happiness. This is important because a smile can activate a constriction of the veins, which would produce cooler temperatures within the body. A frown would act as the opposite, allowing body temperatures to rise. This has to do with the volume of blood around the brain.

This article wisely sums up that while this tactic can improve your mood temporarily, it is not a fix for things like depression and melancholy in general. Those types of processes are much more complex than Zajonc’s hypothesis can fix.

Social Importance of a Smile 

I began to think about how a smile would affect someone else. If you’re smiling, can you improve someone else’s mood? I went searching for information and thought I would find a bunch of sources that described how we as humans like to smile, and like to mimic each other, so we should smile more. Instead, I found an article that explained something called a Duchenne smile and that there are differences in smiling rates for gender. Differences are attributed (in this meta-analysis described) by three things:

  1. Gender Norms
  2. People around us
  3. Culture

The later made me think about all of my research in the context of culture. If smiling is so important to happiness, and there has been a mechanism isolated, what happens if a certain culture frowns upon smiles?


A study coming out of Stanford compared top US leaders to top Chinese leaders. This is an obvious choice when it comes to culture expression differences. Often, Chinese leaders are more reserved and less emotive than US leaders. This has to do with what traits a culture deems important. In the case of the US, we are known to value excitement, whereas Chinese value being calm and reserved.

A study described by the Huffington Post explains that because of some of these cultural differences, it is hard to say that people in the US are “happier” than those in China. This term in and of itself is too vague to really do science at this large of a scale, in my opinion.

This conclusion really made me think of the class where we were talking about if prayer heals. While happiness is a little easier to measure than things as supernatural as prayer, it is still something that science has trouble with. A lot of the research I found had to do with observational studies and self surveys. These can be very valuable tools in science, however, they aren’t as effective as something like a double blind, placebo arm trial that is duplicated over and over again until doubt is something minuscule.

Side note: If smiling has such profound improvements on mood, and mood can enhance concentration and overall functioning, why isn’t this an activity we do all the time? Instead of taking cell phones in class to improve learning, why don’t we just spend time making our minds and bodies feel healthier?

smile face image

3 thoughts on “Smile

  1. Patrick Ryan

    Such a great article to read. I like the topic picked because I find it so simple but it has so many effects in the world. Other than mood I like how you tied in the effects of smiling in social settings, like social norms. Smiling actually has a large effect on our own health, for example depression. According to this article,, smiling has a large effect in stressful situations and can be used as a type of therapy.

  2. Connor Edward Opalisky

    This is a really fascinating post. I have heard before that smiling can improve your mood but I never understood why. The mechanism that you explained makes perfect sense and fits in with common human behavior. I became curious about the effect that smiling has on other people, as you mentioned. I found an article that sites a Swedish study in which participants were shown pictures of several emotions. They found that subjects mimicked the emotions of the pictures they were shown. As it turns out smiling might be one of many emotions that can alter the mood of people around you.

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