Is “discrimination” necessary to explain the sex gap in earnings?

Economists usually assume that any sex difference in earnings after controlling for human capital and occupational segregation is largely (though not entirely) attributable to “discrimination”. From the evolutionary psychological perspective, I argue that “discrimination” (or any other external constraint) is unnecessary to explain the partial effect of sex on earnings if men and women are inherently different in their desire to earn money. From this perspective, reproductive success (rather than earnings) is the ultimate (albeit unconscious) goal of all biological organisms, including humans, and earnings are men's, but not women's, means to reproductive success. The General Social Survey data are consistent with my contention that evolved (not learned) differences in preferences are largely responsible for sex differences in pay, and confirm my prediction that there is no sex gap in earnings among childless unmarried workers under 40. My conclusion is that the sex gap in pay exists because women have better things to do than to earn money, reproductively speaking.