Abstract
The luminance difference between the eyes and mouth and the skin surrounding those features (“facial contrast”) is sexually dimorphic, with females having greater contrast (Russell, 2009). Facial contrast also affects attractiveness, with females rated more attractive with increased contrast (Russell, 2003). Recent work investigating full color images has found that females, but not males, are rated as more attractive when a* (green - red) contrast around the lips is increased (Stephen, 2010). Here we investigated the relationship between facial contrast and age, and between facial contrast and perceived age. Using a set of carefully controlled full face color photographs of 289 women aged from 20 to 69, we measured the contrast between the eyes and the surrounding skin, the eyebrows and the surrounding skin, and the mouth and the surrounding skin, in the CIELab L* (dark - light), a* (green - red), and b* (blue - yellow) axes. There were significant decreases with age in a* (green - red) contrast around the mouth and in luminance contrast around the eyebrow and a weakly significant decrease in luminance contrast around the eye. In a separate study, subjects estimated the age of 150 of these faces. The three aspects of facial contrast that decrease with age (mouth redness, eyebrow luminance, and eye luminance) were also found to predict ratings of perceived age. Faces with greater a* contrast around the mouth, greater luminance contrast around the eyes or greater luminance contrast around the eyebrows were judged to be significantly younger. Together these findings indicate that older faces have less facial contrast than younger faces, and that facial contrast is used by observers to estimate the age of a person from their face.