Red in the Face

photo by nyki_m

What do you find attractive? Rosy red cheeks, perhaps? In humans, red coloration of the skin is usually viewed as a sign of physiological health and attractiveness. The same is true for several bird species and non-human primates; animals often use red coloration as signals for health, social status, hormonal conditions or attracting mates. Researchers at the University of St Andrews in Scotland hypothesized that increased skin blood perfusion would be perceived as healthy and that oxygenated blood color (bright red) of the face would appear healthier than deoxygenated blood color (bluish-red). To test this theory, individuals were shown facial images on a monitor, where color could be adjusted, and asked to change the coloring of the faces until they appeared as healthy as possible. The adjustments in color corresponded to an increase or decrease in facial blood perfusion and oxygen.

The hypothesis proved to be true- blood coloration of facial images was increased, suggesting skin coloration is viewed as a cue to underlying health. Interestingly, when comparing female and male faces, more oxygenated blood color was added to female faces. So how can you get that rosy glow? For women, the formation and widening of blood vessels results in an increase in skin blood color, processes intensified naturally by female hormones and exercise.

Reference: Stephen ID, Coetzee V, Law Smith M, Perrett DI (2009) Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health. PLoS ONE 4(4): e5083. doi:10.1371/journal.pone.0005083