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

Namely: harems are rare in the primate world, conception is statistically rare as well, and rates of miscarriage are high. How likely is it that a male hits the timing of conception just right in a single copulation? Or in multiple copulations with multiple females? Not very. And since such a significant number of pregnancies across species end in miscarriage, stillbirth, and fatal breech births, the math gets even more unfavorable for the male who ejaculates and disappears. Mating and leaving means creating the possibility that the female will mate with another male, and also that his sperm failed to do the job, or that he will not be there to try again if the pregnancy does not result in a healthy offspring. Many scientists have recently come to believe that, given all these factors, the range in male and female lifetime reproductive success actually tends to be equal.