Feminine traits (facial structure with large eyes, full lips, & an oval face shape, & a curvaceous body with relatively large breasts, a narrow waist, & full hips & buttocks) are often claimed to cue women’s reproductive potential; no evidence of this association

Lidborg, Linda H., and Lynda Boothroyd. 2022. “Do Women’s Morphological Traits Predict Reproductive Outcomes? A Systematic Review.” PsyArXiv. August 25. doi:10.31234/osf.io/nhtre

Abstract: Sexually dimorphic – or feminine – traits in women include a neotenous facial structure with large eyes, full lips, and an oval face shape, and a curvaceous body with relatively large breasts, a narrow waist, and full hips and buttocks. Compared to men, women also show higher second-to-fourth finger (2D:4D) ratios as well as less muscle mass and lower physical strength. Due to a putative association with oestrogen levels, feminine traits are often claimed to cue women’s reproductive potential. However, evidence for this purported relationship typically uses reproductive proxies rather than actual biological fitness. Here, we report a systematic review of direct reproductive outcomes as a function of morphological traits in women. The review comprised measures of 2D:4D, voice pitch, and upper-body strength in women from 14 samples, and showed a mixture of null, positive, and negative effects. Given how commonly traits such as facial femininity, WHR, and breast size are claimed to signal fertility, it is noteworthy that we were not able to locate a single study measuring women’s fertility as a function of either of those traits. Overall, our review shows that the current evidence base is too weak to support the claim that women’s morphological traits cue fertility.