Effects of facial identity on age judgments: evidence from repetition priming

The effect of smiling on the perceived age of male and female faces across the lifespan

Previous research has shown an unintuitive effect of facial expression on perceived age: smiling faces are perceived as older compared to neutral faces of the same people. The aging effect of smiling (AES), which is thought to result from the presence of smile-related wrinkles around the eyes, contradicts the common belief that smiling faces should be perceived as younger, not older. Previous research, however, has focused on faces of young adults, where the absence of inherent, age-related wrinkles and other age signs is offset by the weight of the smile-related wrinkles. In a series of experiments, we tested whether the AES extends to male and female faces in older age groups. We replicated the AES in young adults (20–39) and showed that it disappeared in older adults (60–79) of both genders. For photos of middle-aged adults (40–59), however, AES was found only for male, but not for female faces, who showed fewer and less prominent smile-related wrinkles. The results suggest that a person’s apparent age is perceived in a holistic manner in which age-related cues in the region of the eyes are weighted against age cues in other regions of the face.

Smiling makes you look older

People smile in social interactions to convey different types of nonverbal communication. However, smiling can potentially change the way a person is perceived along different facial dimensions, including perceived age. It is commonly assumed that smiling faces are perceived as younger than faces carrying a neutral expression. In the series of experiments reported here, I describe an unintuitive and robust effect in the opposite direction. Across different experimental conditions and stimulus sets, smiling faces were consistently perceived as older compared to neutral face photos of the same persons. I suggest that this effect is due to observer failure to ignore smile-associated wrinkles, mainly along the region of the eyes. These findings point to a misconception regarding the relationship between facial smile and perceived age and shed new light on the processes underlying human age perception.

Emotional expressions of old faces are perceived as more positive and less negative than young faces in young adults

Interpreting the emotions of others through their facial expressions can provide important social information, yet the way in which we judge an emotion is subject to psychosocial factors. We hypothesized that the age of a face would bias how the emotional expressions are judged, with older faces generally more likely to be viewed as having more positive and less negative expressions than younger faces. Using two-alternative forced-choice perceptual decision tasks, participants sorted young and old faces of which emotional expressions were gradually morphed into one of two categories-"neutral vs. happy" and "neutral vs. angry." The results indicated that old faces were more frequently perceived as having a happy expression at the lower emotional intensity levels, and less frequently perceived as having an angry expression at the higher emotional intensity levels than younger faces in young adults. Critically, the perceptual decision threshold at which old faces were judged as happy was lower than for young faces, and higher for angry old faces compared to young faces. These findings suggest that the age of the face influences how its emotional expression is interpreted in social interactions.