Science figured out the key to a perfect smile. Can you master it?


Trying to take a fire selfie? Thankfully, science is here to help you navigate how to perfect your smile.

Researchers at the University of Minnesota explored the good and bad of smiles and published their findings in the journal PLoS ONE.

“A lot of people don’t understand how important their smiles are and how important this aspect of communication we do with each other every day is,” Stephen Guy, a co-author of the research from the University of Minnesota, told The Guardian.

The team of scientists, led by assistant professor of psychology and statistics Nathaniel E. Helwig, recruited participants from the Minnesota State Fair, where they found 802 subjects of various ages (from 18 to 82 years old) and backgrounds.

Each subject was given an iPad with a custom app that had the user view 15 random smiles on computer-animated, 3-D faces for 250 milliseconds each. Subjects were asked to rate them on four qualities: effectiveness, genuineness, pleasantness and perceived emotional intent. There were 27 total faces with varying levels of smiles, mouth angles and amount of teeth shown.

Helwig et al (2017)

The researchers discovered that less is more. Bigger isn’t always better, as they found smiles showing a lot of teeth were rated lower for effectiveness, genuineness and pleasantness. Smiles that developed symmetrically were also rated more favorably.

The findings of the study inform the average person about how smiles are perceived, but there’s a clinical application as well. According to the researchers, the findings can help clinicians working with facial paralysis patients.

And for those worried about their grin, fret not. As the paper notes: “There is not a single path to a successful smile.”