Many of the humanities and social sciences have ignored sexual selection. Sexual selection has two components, intrasexual competition and intersexual selection. The prototypical example of intrasexual competition is buck deer locking horns in combat during the mating season. The winner of the bout gains the territory and access to the females within it. The loser goes home with a broken horn.
Intersexual selection involves both sexes.
If members of one sex have a consensus about the desirable characteristics of the opposite sex, then those individuals with the desired characteristics will have a mating advantage. One example is the size and decorative coloration of feathers seen on many male birds. It is hypothesized that the underlying reason why female birds find a male peacock's tail feathers attractive is their indication of the survival ability of male birds. The feathers would not only be noticeable to females, but also to predators and a hindrance in movement, etc. It would seem easier to survive without this costly display, the females of the species usually possess coloration that blends in well with the features of the habitat.