A new study done jointly by researchers from Ben Gurion University (BGU) of the Negev and Western University of Canada shows people who smile are perceived as being older than those with neutral or surprised expressions.
The researcher conducted a series of experiments intended to gauge age perception based on facial expressions.
In the study, forty BGU students were shown images of people and asked to rank them in age from oldest to youngest.
Participants ranked the smiling faces as the oldest, with those showing neutral expressions next and surprised expressions as the youngest.
However, after the experiment concluded, the students remembered the smiling faces as being the youngest of the lot.
BGU Psychology Deparment's Associate Professor Tzvi Ganel, PhD, said, "When people smiled, they were perceived as between one year to almost two years older than when they were presented bearing a neutral expression."
"Popular media promotes the idea that smiling makes you look younger.
"Look at all of the smiling faces in skincare and dental ads. How many of us post smiling faces on social media?"
Western University of Canada's Brain and Mind Institute Director Melvyn Goodale, who co-authored the study, said, "Ironically, we discovered that the same person can believe that smiling makes you appear younger and judge smiling faces older than neutral ones."
The researchers believe the wrinkle lines formed around the eyes during a smile make a person look older. Surprised expressions, on the other hand, pull the skin backward, smoothing wrinkles out.
The new study, published on May 8 Psychonomic Bulletin and Review, refutes the only other study on the subject of age perceptions and smiling.
The previous study asked participants to rate the age of happy, neutral, sad, angry, fearful, and disgusted faces.
In that study, participants rated the neutral faces as younger than the rest.
However, Ganel suggested flaws in the previous study's methods, and said participants' perceptions were biased after viewing the other facial expressions.
In his own study, Ganel conducted three experiments on a total of 60 participants.
In his first experiment, Ganel found participants rated smiling faces as being older than neutral faces.
His next two studies focused on making the "smile lines" more noticeable and blurred, respectively. However, both of the second two produced the same results, with participants consistently rating the smiling faces as being older than the non-smiling faces.