Do women’s morphological traits predict reproductive outcomes? 1 A systematic review 2 Linda H. Lidborg¹* & Lynda G. Boothroyd¹ 3 1. Department of Psychology, Durham University, South Road, Durham, DH1 3LE, U.K. 4 *Author for correspondence: lhlidborg@gmail.com 5 Word count: 4,759 6 Keywords: sexual selection; sexual dimorphism; femininity; biological fitness; fertility; 7 reproduction; reproductive success 8 9 Abstract 10 Sexually dimorphic – or feminine – traits in women include a neotenous facial structure with 11 large eyes, full lips, and an oval face shape, and a curvaceous body with relatively large 12 breasts, a narrow waist, and full hips and buttocks. Compared to men, women also show 13 higher second-to-fourth finger (2D:4D) ratios as well as less muscle mass and lower physical 14 strength. Due to a putative association with oestrogen levels, feminine traits are often claimed 15 to cue women’s reproductive potential. However, evidence for this purported relationship 16 typically uses reproductive proxies rather than actual biological fitness. Here, we report a 17 systematic review of direct reproductive outcomes as a function of morphological traits in 18 women. The review comprised measures of 2D:4D, voice pitch, and upper-body strength in 19 women from 14 samples, and showed a mixture of null, positive, and negative effects. Given 20 how commonly traits such as facial femininity, WHR, and breast size are claimed to signal 21 fertility, it is noteworthy that we were not able to locate a single study measuring women’s 22