Variations in the sexuality of self-identified heterosexual women are related to preferences for male facial masculinity, according to new research published in International Journal of Sexual Health.

The study found that more than half of heterosexual women reported at least some attraction to women, which in turn was related to their assessments of male attractiveness.

“I was interested in this topic because much of my research examines what makes some women prefer more feminine-looking men while other women prefer more masculine-looking men,” said study author Carlota Batres, the director of The Preferences Lab and an assistant professor at Franklin & Marshall College.

In the study, 27,611 heterosexual woman completed an online questionnaire in which they reported their level of sexual attraction to women, level of sexual attraction to men, hormonal contraceptive use, relationship status, attitude toward casual sex, and self-assessed attractiveness. The participants were then shown pairs of male faces and instructed to select which face from each pair they considered to be the most attractive.

The researchers blended photographs of multiple men and women to create a set of composite faces that varied in masculine features.

Even though all the women identified as heterosexual, 62.60% of them reported some level of sexual attraction to other women. Batres and her colleagues found that women with higher levels of attraction to other women were more likely to view less masculine-looking male faces as more attractive.

“This suggests that the continuous nature of female sexuality is reflected in preferred partner characteristics,” the researchers wrote in their study.

“The average person should take away that there are several factors that influence women’s masculinity preferences. For example, in our study, we found that level of sexual attraction to men, level of sexual attraction to women, relationship status, hormonal contraceptive use, age, and self-perceived attractiveness all influenced preferred masculinity levels,” Batres told PsyPost.

In particular, single women, older women, and women who considered themselves attractive were more likely to view more masculine-looking faces as attractive.

“This study only used women who self-identified as heterosexual and further research would benefit from exploring preferences across the gender spectrum (e.g., transsexual women) as well as across the sexual orientation spectrum (e.g., pansexuality),” Batres said.

The study, “Attraction to Men and Women Predicts Sexual Dimorphism Preferences“, was authored by Carlota Batres, Benedict C. Jones, and David I. Perrett.