This Is Why Smiling Is So Freaking Contagious, According To Science

By the time you reach your 20s, you've most likely heard your fair share of comments from people telling you to smile, especially if you're a woman. And while there's certainly a case to be made for how frustrating it is to be told to smile when you're just walking down the street and minding your own business, you can't deny that there's something about smiling (and even frowning) that makes it spread around a room like wildfire. So is smiling really contagious, or is it just one of those things you were told as a kid to make you grin and bear it through bad play dates or a trip to the dentist?

Sure, smiling might not be an airborne pathogen or a virus, but a toothy grin can technically still be contagious. According to a 2016 study published in the journal Trends in Cognitive Sciences, as humans, pretty much all of our facial expressions can be contagious, including smiling. This mimicry is basically an instinctual attempt to understand what another person is feeling, the study explained. What's more, by smiling back at someone who smiled at you, you're actually triggering the emotion to go along with it, which is another evolutionary tool that further helps us understand how other people are feeling in social situations. The study authors wrote,

Emotions are patterns of expressive, behavioral, physiological, and subjective feeling responses. Activation of one component can therefore automatically activate other components.

In other words, the contagiousness of facial expressions are an evolutionary benefit that allows you to put yourself in another person's shoes.

If you've ever been in a job interview before, then you probably know exactly what this is like: Your interviewer nods, and you nod back to let them know you understand what they're saying. And then they smile, and you find yourself smiling even bigger for some reason. Then they frown to talk about something more serious, and you frown back to let them know you're capable of being serious, too. Demonstrating such a big range of emotions in a matter of minutes can be pretty exhausting, especially in a situation like that, but the truth is, people do this all the time, and oftentimes in much more relaxed settings. It's simply how we communicate with one another.

In addition to helping you feel empathy for other people, smiling is contagious because it makes you feel good from the inside out, which in turn can trigger a smile of your own. To state the obvious, a smiling person is usually seen as more approachable, or even attractive, but there's more to it than just that. When you see someone smile, you're unconsciously absorbed by it because, according to Penn State University, it can "trigger the feeling of reward" in your own body. In other words, when someone smiles at you, you instinctively think that you must have done something good to deserve this smile, and as a result, this makes you feel happy. And, on a more physical level, since smiling is said to trigger a release of dopamine and serotonin (aka the feel-good chemicals) in your body, this only makes your reward response that much stronger. What's more, you're pretty likely to smile back, thus perpetuating the cycle altogether, and proving all on your own that smiling really can be contagious.

But it's not just in intimate settings, or even in artificially-constructed ones, where you'll notice the power behind a simple smile.

Even smiling within the broader scope of an entire community is said to be just as contagious as the grins exchanged in one-on-one settings.

According to a 2008 study published in The BMJ medical journal, which tracked nearly 5,000 people in the town of Framingham, Massachusetts over the course of 20 years, a person's level of happiness can largely be determined by the network of people around them. In other words, if you live in a neighborhood where people are smiling a lot, then you probably have a big ol' grin plastered across your face more often than not, too. Nicholas Christakis, a professor in Harvard University's sociology department and co-author of the study, told Fox News,

Happiness is like a stampede. Whether you're happy depends not just on your own actions and behaviors and thoughts, but on those of people you don't even know.

So go ahead and conduct your own experiment: Try to smile a little more often each day, and when you do, pay attention not just to how it makes you feel, but also how it seems to affect the people around you, too. You never know who might be smiling back at you.