often be imprinting on a social father who is not their biological father, and possibly has not reproduced at all 9. As to female spiders, they may have no other option than imprinting on a chivalrous mature male (not right after hatching but as "teenagers" 5) since they receive no care whatsoever from parents; the same goes for fruit flies 12. When males are themselves the choosy sex, as in numerous species of fish, the imprint-on-the-winner logic can be transferred to them: sons ought to imprint on mothers (see 13). This time around, it is mothers who have emerged from the struggle with other females to be chosen by a male. Yet the notion that sexes are either entirely choosy or entirely competitive has been challenged even in species with uniparental care (reviewed in 14), and surely falls short of describing our own mating system. In humans, females are arguably the choosy sex (e.g. 15) but also engage in considerable courting and competing, and males court and compete a great deal but do some rejecting too (e.g. 16).