University study: Smile to look younger, thinner

KANSAS CITY, Mo. -- Recent research from the University of Missouri- Kansas City suggests smiling may make people appear younger and thinner.

When you smile, other people tend to see you as younger than if you are staring back with a neutral expression or frown.

If you frown, you look heavier, according to two pieces of research from the University of Missouri-Kansas City's psychology department and the lab of professor Seung-Lark Lim.

The research, published in the March 30 edition of the journal PLOS ONE, was led by Norah Hass, a third-year psychology doctoral student.

"The take home is interesting in that maybe having a positive expression will make you look younger," Hass said. "We can see this very clear shift of sad emotion versus happy emotion. Unless you're trying to look old, I'd recommend you try not to look so sad and look happy."

The research involved asking college students to sit in front of a computer and look at a range of images of male faces split into age groups ranging from about 30 to 65. Some of the faces were smiling; others had neutral expressions.

The study participants were asked to judge the faces, within their age groups, as "young" or "old." Hass found no matter the age group that happy, smiling faces were judged as "young" far more often than faces with neutral expressions. Neutral faces were seen as older in each age group than their happy counterparts.

In another recent study, UMKC undergraduate psychology student Trent D. Weston asked college students to judge the weight of people based on hundreds of randomized faces that flashed on a computer screen. Some faces looked sad, and other had neutral expressions.

The sad faces tended to be judged as heavier, according to the study.