In Chapter 9, Dawkins argues that mating is all about exploitation since they do not share genes. Their only investment to each other is their shared genes in the form of a child, but it would be more beneficial to mate A to trick mate B into giving their child all of their parental investment so mate A can go ahead and spread more of their genes. For practical purposes, Dawkins calls the mate with the energetically expensive gametes “female” and the mate with the energetically less expensive gametes “male” for every species. Because females invest into reproduction than males even before conception, Dawkins claims this is exploitation. Males benefit from female investment without putting as much energy in themselves. Because females invest more in their offspring from the beginning, they are less likely to reject their child because they have more to gain if the child survives. Males invest less upfront, so they can go ahead and move on to spreading more of their genes once the child is conceived. Females would be at advantage if they didn’t have to provide all of the parental investment, so it is to their benefit to either make the male stay or trick another male into staying. To prevent these tricks, males develop strategies to make sure the female isn’t making them invest energy on a child that isn’t theirs, like long courtships to make sure the female isn’t pregnant or just killing all children when the male comes into the picture.
The selfish gene also explains sex ratios. Theoretically, it would makes sense for only a couple males exist and then mate with many females so the males could pass on more of their genes. However, the females then lose out on passing on their genes. Equal sex ratios are the equilibrium result of both sides trying to exploit the other.
Dawkins then goes into quite a sexist theory wondering what the benefits of long courtships are for either sex. He calls females that force males to court them for a long time “coy” and females that will just give it up “fast.” Males who ditch their partners are “philanderers” and males who stick with their mates “faithful.” The most evolutionary stable strategy is for most females to act coy and for most males to act faithful, but the ones who cheat this system and are the few females acting fast or few males acting philanderous will have the advantage.
In the end, both males and females just want to have the maximum amount of children that will be successful in passing on their genes. For females, this means surviving to make the expensive gamete. For males, it means convincing the sex with the expensive gamete to take theirs. Dawkins believes this is why sexual selection favors the “sexy sons” with flashy traits, like colorful feathers, and drab, choosy females that exist to survive and bear the chosen ones children. Humans are the exception, because, of course, human females are dumb and they have to be the flashy sex and the sex with the expensive gametes. They just don’t know better, poor things, and can’t outsmart the amazing human male.