Hormonal correlates of women's mid-cycle preference for the scent of symmetry

Over a dozen studies now report increases in women's preferences for various male traits at high fertility points in the menstrual cycle — namely, traits that, purportedly, were ancestral indicators of good genetic quality. Very few studies have examined the proximate mediators responsible for these preference shifts. The current study was designed to examine possible proximate mediators of one of the most thoroughly studied preferences shifts: women's mid-cycle preference for the scent of male symmetry. Based on women's cycle length and day of the cycle, we estimated their levels of estrogen, testosterone, progesterone, prolactin, follicle-stimulating hormone and luteinizing hormone for three separate samples of women. Through regression analyses, we then examined which hormone levels predict cyclically shifting preference for the scent of male symmetry. Progesterone negatively and estrogen positively predicted women's preferences for the scent of symmetry.