Untrue: Why Nearly Everything We Believe About Women, Lust, and Infidelity Is Wrong and How the New Science Can Set Us Free

by Wednesday Martin

By copulating with a slew of males when she wasn’t in estrus or fertile—basically by having sex recreationally—a female primate could deplete the sperm available to rival females. She could recruit males to her social group, thus having more potential caregivers and protectors and provisioners. She could trade sex for resources or “friendship.” Of course Hrdy’s female langurs didn’t have some conscious endgame. They didn’t mate multiply because they figured, “Hmmmm, better confuse the issue of paternity and line up multiple possible ‘dads’ to protect my baby” instead of attack it. Nor did other primate females think, “Boy, would I ever like to increase my odds of heterozygosity” or “get some really good genes,” or—in species where male support is essential—get several males to care for or provision her offspring, thinking, “I need to line up several providers.” Females solicited males because they were conditioned to additional matings that might feel good. And it felt good because of the way ancestral female primates were built.