Scientists have long known that women's preferences for masculine men change throughout their menstrual cycles. A new study from Indiana University's Kinsey Institute is the first to demonstrate differences in brain activity as women considered masculinized and feminized male faces and whether the person was a potential sexual partner.
The researchers identified regions of the brain that responded more strongly to masculine faces and demonstrated that differences between masculinized and feminized faces appeared strongest when the women were closer to ovulating.

The study, published in an online edition of the journal "Evolution and Human Behavior," sheds light on the link between women's hormone levels and their brain responses to masculinized versus feminized male faces, potentially offering insights into female mate preferences. The current study points towards enhancements of both sensory discrimination and risk processing around ovulation in response to masculine faces as possible mediators of women's mate preferences.