Smile Science

I have a vivid memory of one Saturday night riding in the car with my parents on our way back from my 4K choir concert. My frequently hungry self was buckled into my car seat next to my two siblings and we watched in excitement as the golden arches came into view.“MOM?! CAN WE GO TO MCDONALDS?!?” I yelled as we quickly sped passed the entrance.“Not today sweetie, I already bought some chicken for dinner,” my smile quickly turned to a frown. My Dad turned around, “Aww c’mon honey, give us a smile!” I faked an even deeper frown causing my Dad to laugh. I laughed, then he laughed, and soon I was wearing a grin ear-to-ear.

Smiling… it’s not something we think much about, we just do it. Yet behind it’s façade of simplicity, there lies a science that affects our emotional and physical health, and the way with which we approach life

The Emotional Affects of Smiling 

So, what effects does smiling have on your emotional state? When your facial muscles contract into a grin, this muscle movement has a cascading effect causing a positive feedback loop. This positive feedback loop involves signaling to the brain to increase the level of various “happy hormones,” including: serotonin, dopamine, and endorphins (1). These neuropeptides work to promote good feelings and fight off stress and are the other element of the positive feedback loop. Neuropeptides are multifunctional, and can act as natural pain relievers and anti-depressants.

Bestselling author and positive psychology researcher, Shawn Achor, believes that that frequent smiling also helps you create positive thinking “pathways.” He admits that forming these upbeat ways of thinking is not easy; negative thoughts can be invasive and hard to shut out. Achor describes this process in his book, “The Happiness Advantage,” when he states, “happiness is a work ethic. It’s something that requires our brain to train, just like an athlete has to train” (2).

The Physical Effects of Smiling 

The physical health of the smiler is also improved through the release of various “happy” chemicals. A decrease in stress means lower heart rate and blood pressure, a stronger immune system, and better endurance. In a study done at the University of Kansas, students were divided into three groups and given chopsticks to assist in modeling facial expressions (3). One group was told to make a neutral expression, one a genuine (Duchenne) smile, and the other was told to make a standard smile. They were then given a stressful task to do while holding these faces, and their heart rates were monitored. Those who held a Duchenne smile had the best heart rate recovery after the activity, followed by those with the standard smile, and finally those with the neutral expression took the longest to recover. The results of this study strongly suggest a connection between smiling and a person’s capacity to handle the physical components of stress.

Smiling can help others

Everyone has heard the expression smiling is contagious, and the story I told earlier is a perfect example. While smiling may not be contagious in the same way that a cold or the flu is, your smile can prompt others to smile, spreading good feelings around. The first element to the contagious smile is our capacity to mimic those around us. In a study done by social psychologists at the University of Wisconsin-Madison, there was strong evidence suggesting that humans use facial expression mimicry to empathize with others (4). When a person smiles at you, your brain replicates that facial muscle action, triggering memories associated with that movement, and in turn causing an emotional reaction. This emotional reaction is what allows you to understand what the person is feeling and act accordingly. The other element that factors into the contagious nature of smiling is how people perceive the facial expression. Researchers at Penn State University conducted a study comparing the demeanor of members of a customer service staff to the overall satisfaction of the customer and their perception of the staff member (5). The results showed that members of the staff that smiled were more often perceived as honest and likeable; in turn, the customers were more likely to be open and smile back. This suggests that genuine smiling is reassuring to those around, and shows that perceptions about the characteristics of people who smile contribute to others’ willingness to return the smile.

Before doing research for this article, I had no idea that a smile was anything more than a simple show of emotion. The power of this facial expression made me take a step back and look at what I value. I realized that prioritizing the people and experiences in life that help you reach that genuine smile is key. Smiling has the potential to improve not only our physical and mental well-being, but also the well-being of those around us!


  1. Riggio, Ronald E. “There’s Magic in Your Smile.” Psychology Today, Sussex Publishers, LLC. , 25 June 2012,
  2. Achor, Shawn. “Happiness Is A Work Ethic.” Big Think, The Big Think Inc. , 29 June 2013,
  3. Warmink , Harry. “Grin and Bear It! Smiling Facilitates Stress Recovery.” Association for Psychological Science, Association for Psychological Science , 20 July 2012,
  4. Cell Press. “Why smiles (and frowns) are contagious.” ScienceDaily. ScienceDaily, 11 February 2016. <>.
  5. Grandey, Alicia, et al. “Is ‘Service with a Smile’ Enough? Authenticity of Positive Displays during Service Encounters.” Egyptian Journal of Medical Human Genetics, Elsevier, 5 Nov. 2004,
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Seffie is a Social Media Intern at Promega. She recently graduated from the University of Wisconsin-Madison with a BS in Genetics, and has strong interests in scientific communication and digital marketing. In her free time she enjoys writing for her fashion blog, skiing, and hanging out with her two dogs, Finn and Duffy.

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