You may be interested in reading about evolutionary psychology. This covers not only the evolved selection mechanisms pertaining to our species but also in certain cases covers basic reproductive economics. For a man, sperm is a cheap renewable resource so one very successful strategy for passing on one's DNA is to mate with as many females as possible. For women, however, eggs are infrequent (once per month, for a limited number of years), gestation is very metabolically expensive, and child-rearing is equally as expensive in terms of time and effort. Thus women must be very careful (choosey) about the male they permit to contribute 50% of the DNA to a potential offspring. Will he stick around and help with the child-rearing? Does he have good genes so the child will have a competitive advantage when it grows up and needs to mate? We're all just DNA reproduction machines; our "free will" is a hilariously fragile illusion compared to the predictability of our hardwired behaviors - which operate largely without us even being aware of them.