Women lips coloration as a signal of fertility and quality
Résumé
Several primate species exhibit red skin coloration that can communicated emotional state, dominance status, health condition, and fertility. When we are asked to picture colorful traits of female primates, we can easily think of the shiny sexual swelling of baboons, the geladas' “bleeding heart”, or the Japanese macaques' red mask. We usually don’t picture woman traits. Women seem to lack obvious and/or exaggerated traits of their fertility and/or quality. However, several studies have suggested that men may be able to pick up some facial indices of women fertility, such as variation in skin smoothness and brightness around ovulation. But none has investigated the possible role of the most colorful and appealing trait of the women face, i.e., lips. Women lips are subconsciously connected to fertility and beauty and women seem to compete with each other according to women and men's psychological standard of beauty. This study is the first attempt to investigate the relationship between women fertility, quality and lips coloration, i.e., whether darker/redder lips are associated with ovulation signaling or quality signaling (e.g. parity), from signal content to signal perception (men and women). This study aims to enhance our understanding of how female colorful sexual signals have evolved in non-human and human primates, using methods inspired from primate studies.