A COUPLE of evolutionary psychologists recently published a book about human sexual behavior in prehistory called “Sex at Dawn.” Upon hearing of the project, one colleague, dubious that a modern scholar could hope to know anything about that period, asked them, “So what do you do, close your eyes and dream? Evolutionary psychologists who study mating behavior often begin with a hypothesis about how modern humans mate: say, that men think about sex more than women do.
Then they gather evidence — from studies, statistics and surveys — to support that assumption.
That, for instance, society tends to view promiscuous men as normal and promiscuous women as troubled outliers, or that our “social script” requires men to approach women while the pickier women do the selecting.
Over the past decade, sociocultural explanations have gained steam. Everyone has always assumed — and early research had shown — that women desired fewer sexual partners over a lifetime than men.
The evolutionary psychologists of the 1980s and ’90s built on Mr. Schmitt used parental investment theory to explain why men should be expected to “devote a larger proportion of their total mating effort to short-term mating.” Because men invested less time and effort in their offspring, they evolved toward promiscuity, while women evolved away from it.
As for going to bed with the confederate, zero women said yes, while about 70 percent of males agreed.
Finally, and here’s where the leap occurs, they construct an evolutionary theory to explain why men think about sex more than women, where that gender difference came from, what adaptive purpose it served in antiquity, and why we’re stuck with the consequences today.