INTRODUCTION

1. 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 50-55 55-60 60-65 65-70 Visible Skin Color Distribution Plays a Major Role in the Perception of Age, Attractiveness and Health in Female Faces Fink, B.*, Grammer, K.♦, Burquest, M.H.¶ and Matts, P.J.† *Department of Anthropology, University of Göttingen, Germany; ♦Ludwig-Boltzmann Institute for Urban Ethology, Vienna, Austria; ¶ Procter & Gamble, Cincinnati, Ohio, USA; †Procter & Gamble, Egham, Surrey, UK INTRODUCTION OBJECTIVE RESULTS CONCLUSION We have hypothesized previously that low contrast and brightness are key optical parameters of attractive, healthy skin and that color is at least as important as topography in affecting these endpoints. Contrast can easily be created by color if a homogeneous field is disrupted by colored features of either sufficient diameter and / or ratio of adjacent luminance. This is, indeed, precisely the effect observed in ageing (particularly photodamaged) human skin, in features composed of both melanin and hemoglobin. Skin color distribution, therefore, is potentially an important visual cue of human health and beauty and, yet, remains remarkably unstudied. To study the single-variable contribution of skin color distribution to perception of age, attractiveness and health in female human faces, independent of facial form, feature and skin surface topography. The estimated biological age (aggregated estimates from all judges for each face) of facial images ranged from 17.8 to 36.7 years, a span of some 20 years and there was a highly significant positive correlation between the actual biological age of the subjects who provided facial images and the corresponding estimated age of their 3D shape-standardised faces varying only in visible skin colour distribution (rho= .721, p< 0.01, 2-tailed). Significant negative correlations emerged between estimated facial age and the global face attributes (attractive: rho= -.527, p< .01; healthy: rho= -.520, p< .01; youthful: rho= -.860, p< .01). In summary, therefore, we can conclude that skin colour distribution alone, independent of facial form, feature and skin surface topography can influence perceived age within a range of 20 years. Furthermore, it also appears to influence significantly perceived “attractiveness”, “youth” and “health”. Strategies to improve the appearance of ageing skin, therefore, need to focus not only contrast created by form and topography, but also that created by color distribution and the chromophore targets responsible for this. b a In this stage, facial features (e.g. pupils, mouth gap, etc.) were standardized geometrically by fitting these to fixed addresses within the 2D template. To generate 3D facial stimuli from 2D colour maps, faces were deformed to match a template grid in order to fit on a shape-standardised wire-frame mesh. In the final rendering process, these corrected 2D maps were fitted to the wire-frame mesh, akin to a virtual skull. In this process, we added standardised facial features (eyes, nose, mouth, ears, hair, etc.) such that the resulting dataset comprised 169 3D head / face stimuli, standard in every respect apart from the subject’s original skin colour distribution. An example of this process is shown in the panel opposite. These stimuli were shown blind to 430 members of the public, aged 13-76, in Germany and Austria using calibrated monitors. Participants were requested to estimate the biological age of each face using a single-step scale ranging from 10 to 60 years. In addition, participants were asked to rate each face for a total of 15 attributes using a 10-point rating scale combining aspects of perceived attractiveness and health and apparent skin condition. (a) 2D template (b) 3D wire-frame mesh (front and right) (a) Original frontal image (b) lines / furrows removed METHODS 169 Caucasian women aged between 10 and 70 were imaged from front, left and right views using a custom high-resolution digital imaging system. The use of cross-polarised lighting eliminated fine surface texture in this imaging stage. The resulting images were processed using a new, unique series of digital manipulations to create “stimulus” heads where skin color distribution was the only remaining variable: Left and right sides were “grafted” onto the frontal image and then a cloning technique was used to remove any contrast attributable to low-frequency topographical features (lines / furrows, etc). 2D color maps were than created by fitting the resulting image to a standard 2D template. Image above (b) fitted to 2D template Image left deformed before 3D rendering Original image Final stimulus 30 28 26 Estimated Age 24 22 20 References Fink, B. & Grammer, K. & Thornhill, R. Human (Homo sapiens) facial attractiveness in relation to skin texture and color. Journal of Comparative Psychology, 115(1), 92-99, 2001 Matts, P.J., Understanding and measuring the optics that drive visual perception of skin appearance, in “The essential stratum corneum”, Marks, Leveque, Voegeli (eds), Martin Dunitz, London, 213-222, 2002 Actual Age (5 year groups) Actual age = 12 Estimated age = 20 Actual age = 42 Estimated age = 24 Actual age = 55 Estimated age = 31 Examples of final rendered stimuli with actual and estimated ages. Note the range of appearance attributable to colour distribution alone. LSD ANOVA plot (means and confidence intervals) of actual chronological age (5 year cohorts) vs estimated age This work was funded by P&G Beauty