  This theme is carried through in his discussion in Sexual Selection in Relation to Man, in which hunting, defense of self and community, and competition for mates result in the development of men's “observation, reason, invention and imagination.” Women obtain these traits because they inherit them from their fathers. Darwin writes that “It is, indeed, fortunate that the law of the equal transmission of characters to both sexes prevails with mammals; otherwise it is probable that man would have become as superior in mental endowment to women, as the peacock is in ornamental plumage to the peahen” (Darwin, 1871, 565). Whereas Darwin believed that male-male competition was generally thought to improve the species, female choice resulted in the development of beauty without utility: “a great number of male animals… have been rendered beautiful for beauty's sake” (Darwin 1859, 371); “the most refined beauty may serve as a charm for the female, and for no other purpose” (1871, vol. 2 92). In this view, the expensive and dangerous displays of the peacock are the result of the preference of females for males with the most beautiful display. It is worth noting that Darwin developed his notions of female choice to account for traits that seemed to be maladaptive from the perspective of natural selection alone.