Smiling Really Is Contagious, And Here’s Why

When you beam at someone, a lot happens during that interaction without you knowing it.

It turns out that not just our grins, but all of our facial expressions are contagious, according to a paper published in the journal Trends in Cognitive Sciences on Thursday. 

We tend to mimic the smiles or frowns of others because it helps us better understand what other people are feeling, allowing us to respond appropriately.

Adrienne Wood, a Ph.D. student in psychology at the University of Wisconsin-Madison and lead author of the paper, told The Huffington Post that “sensorimotor simulation” in our brains is what causes this bizarre mimicry to occur without us even realizing it.

“When you see a facial expression and you want to know what it means, you recreate that expression in your brain,” Wood said. “In daily life, you rarely observe facial expressions in a vacuum, and we believe that you combine information from sensorimotor simulation with your understanding of the situation in order to fully comprehend other people’s feelings.”

For the paper, more than 120 previous studies were reviewed to help describe how exactly we simulate the facial expressions of others in social situations.

Based on their review, the researchers concluded that when we mimic someone else’s facial expression, we trigger that same emotional state in ourselves, which then allows us to formulate an appropriate social response.

“Our own lab has shown that making eye contact is one of the easiest ways to elicit facial mimicry,” Wood said. “It probably sounds obvious, but if you want someone to really understand how you feel, or you want to understand how someone else feels, look them in the eyes.”