Skin carotenoid colouration: a signal of current health
Recently, the importance of skin colour for facial attractiveness has been recognised. In particular, within ethnicity variation in skin colour linked to dietary intake of carotenoids has been proposed as a signal of health and consequently attractiveness. However, several important questions are outstanding: Are preferences specific to carotenoid colouration and are they specific to faces? Do preferences for carotenoid colouration extend to other social judgements? And, what are the physiological mechanisms underlying carotenoid colouration of the skin? Here, in a series of experiments with Caucasian participants, we investigated the perceptual significance of carotenoid induced skin colouration for attractiveness and trust judgments, as well as associations between this skin colouration and testosterone. We find high carotenoid colouration: (a) is preferred to low carotenoid colouration and to high melanin (suntan) colouration; (b) is preferred in the context of a face but not in the context of scrambled face patterns; (c) is associated with social judgements such as increased trustworthiness; and (d) is associated with low baseline and reactive testosterone levels in men. Taken together these findings are consistent with skin carotenoids providing a colour signal of current condition in humans and indicate an intricate physiological interplay between diet, hormones and immune function in control of carotenoid levels.