I tend to disregard this "common sense" pop culture knowledge, because it's one of those things people say without evidence, and which often tend to be wrong.
I would love to see someone explain the link between taboos about sex and male paternity claims, but so far I see not a single (even dubious) reference from subject matter experts, so I will continue being skeptical about this claim.
If I were a man in power and i wanted to protect myself from investing effort into raising children that don't carry my genes, I'd definitely try to establish a taboo around women having sex with multiple partners.
And maybe it's possible that if you don't also have taboos around even talking about sex, then the former taboos wouldn't be sustainable. But it seems just as likely that a society that talks freely and openly about sex would be one in which paternity would be easier to establish, because it would be common knowledge which sexual partners a woman claiming to carry your child had.
It seems like it should be a topic covered by Diamond's "Why is sex fun" but I can't remember an exact section devoted to taboos (nothing in the index etc.).
I would love to see someone explain the link between taboos about sex and male paternity claims, but so far I see not a single (even dubious) reference from subject matter experts, so I will continue being skeptical about this claim.
"It's obvious!" doesn't convince me.