SCIENCE: Why Societies Sanction Female Promiscuity:

Results of both studies were consistent with the theory that opposition to promiscuity arises in circumstances where paternity certainty is particularly important and suggest that such opposition will more likely emerge in environments in which women are more dependent economically on a male mate. . . .

In other words, the more dependent on men women are, the higher the reproductive stakes: If you get pregnant and can’t make a strong case that a given man was the father, you (and your child) could be in serious trouble.

This is a pretty old-school way of looking at things, of course, but that’s the point: Not all aspects of human culture are caught up to modern life. As the researchers write, these “beliefs may persist due to cultural evolutionary adaptive lag … that is, because the environment has changed faster than the moral system.” Today, thanks to modern contraception, when we want to separate sex and reproduction, we can do so with a very high success rate. Many of our older and more conservative ideas of morality may have developed before this was the case.

Even in modern life, paternity fraud is a problem. In response to an earlier post on this subject, a reader who asks anonymity writes:

I am familiar with a massive ongoing multi-generational genetic study. . . . (Please don’t mention either it or my name.) The participants were predominantly “greatest generation” and their kids’ generation. Middle-class and white a bit more than the general population. It was looking for hereditary cancers (not too common, maybe 10% or so, last time I checked).

But, of course, in the process of all this, they discovered so-called “false paternities”. (Their rules prohibited them from divulging this info to participants.) Anyway, the overall false paternity rate for this bunch from the “Leave it to Beaver demographic” was about 16%.

16%. One in six. In middle America. Not your mom, of course, nor mine, but hey, that’s going to be a lot of data to discuss around the dinner table.

Just thought you might enjoy some numbers!

We could bring things up to date for this new era of reproductive science, of course, with mandatory paternity testing at birth.