When we don't know what we know - Sex and skin color.

In 3 experiments, we examine how the abstract category of gender, grounded by the lightness-darkness dimension, derived from the universal sexual dimorphism of skin color, is represented and how such representations lead to visual accentuation processes, i.e. polarization of differences between male and female faces. In the first two experiments, we show that irrespective of whether grayscale male and female faces are presented sequentially or jointly, female faces are judged to be lighter than male faces when participants are asked to indicate the level of lightness of the faces. This pattern was found for the majority of participants who explicitly stated that men and women do not differ in skin color. The third experiment was designed to examine the cognitive consequences of what people implicitly 'know' with a perceptual accentuation study. Participants were provided with male and female faces of equal skin color. Subsequently, in a memory recall task, they were asked to select, from a row of several faces varying in skin color, the original face. They chose, as predicted, lighter versions of faces for females compared to the male faces. This research reveals that the evolutionarily based sexual dimorphism in skin color implicitly grounds gender categories and shapes implicit visual accentuation processes.