God, Professor Cordelia Fine is so smart and so funny. She's my academic equivalent of Terry Pratchett.
In her book Testosterone Rex she brings up an oft-repeated claim (which I'm pretty sure I first heard in high school - my wife says she never did, but then her school had a nicer culture than mine) that "one man can produce as many as 100 offspring by indiscriminately mating with 100 women in a given year, whereas a man who is monogamous will tend to have only one child with his partner during that same time period." So, (says David Schmitt of Bradley University, with whom this claim apparently originates) it makes sense that men want a lot of partners while women only want one. Blah blah my prejudices are actually just science blah.
Okay, says Professor Fine, let's take a look at those numbers.
Assume the man can find a willing woman, and persuade her to have no-strings-attached unprotected sex (which sounds like it would be a bit of a challenge in the modern age, and even more so through all of preceding human history and prehistory). Assume he manages that feat 100 times in the course of a year. Assume that he restricts himself to women over twenty and under forty, assume that he always has enough sperm kicking around to successfully inseminate someone, even assume that he's restricting himself to women who are currently ovulating.
(she does not say "assume that he is always having the kind of sex likely to result in pregnancy," which also seems pretty unlikely to me. You're saying this man wants to sleep with a different woman every three days, and he's not going to cum on someone's titties even once? Impossible)
Even in this vanishingly unlikely scenario, given the roughly 8% chance that such encounters would result in a child, our hypothetical man's chance of making a hundred babies is given at...
That's more than one hundred zeroes after the decimal point. Seems improbable. Perhaps more crucially, Fine suggests that "a promiscuous man would need to have sex with more than 130 women just to have 90 per cent odds of outdoing the one baby a monogamous man might expect to father in a year." So the idea that men are wired to sleep around while women are made to seek one single partner seems...unsupported. Or, as Professor Fine acidly concludes:
"And they say feminists are wishful thinkers."