In the NYT, Carl Zimmer covers a topic I went over a few years ago in Taki’s Magazine:

Fathered by the Mailman? It’s Mostly an Urban Legend

Carl Zimmer MATTER APRIL 8, 2016

Five days a week, you can tune into “Paternity Court,” a television show featuring couples embroiled in disputes over fatherhood. It’s entertainment with a very old theme: Uncertainty over paternity goes back a long way in literature. Even Shakespeare and Chaucer cracked wise about cuckolds, who were often depicted wearing horns.

I’d say “especially” rather than “even.” Who is related to whom is an extremely fundamental topic and thus comes up all the time in the most important literature, such as Oedipus Rex. Similarly, Hamlet revolves around Hamlet’s fear that the prince’s uncle-stepfather might decide to make his own heir with Hamlet’s mother. (This gets confused in stagings because the character Hamlet appears to have been originally intended to be about 16 years old, suggesting his mother was in her still fertile 30s. But Shakespeare, feeling his oats, expanded Hamlet’s role into the biggest, most spectacular one in English literature, so we assume Hamlet is about 30, which makes the role a rite of passage for youngish star actors, such as, recently, Benedict Cumberbatch. But this adjustment in Hamlet’s age reduces the prima facie plausibility of Hamlet being worried about his mother cuckolding him out of his inheritance.)

But in a number of recent studies, researchers have found that our obsession with cuckolded fathers is seriously overblown. A number of recent genetic studies challenge the notion that mistaken paternity is commonplace.

“It’s absolutely ridiculous,” said Maarten H.D. Larmuseau, a geneticist at the University of Leuven in Belgium who has led much of this new research.

The term cuckold traditionally refers to the husband of an adulteress, but Dr. Larmaseau and other researchers focus on those cases that produce a child, which scientists politely call “extra-pair paternity.” …

It wasn’t until DNA sequencing emerged in the 1990s that paternity tests earned the legal system’s confidence. Labs were able to compare DNA markers in children to those of their purported fathers to see if they matched.

As the lab tests piled up, researchers collated the results and came to a startling conclusion: Ten percent to 30 percent of the tested men were not the biological fathers of their children.

Those figures were spread far and wide, ending up in many science books. But the problem with the lab data, Dr. Larmuseau said, was that it didn’t come from a random sample of people. The people who ordered the tests already had reason to doubt paternity.

Dr. Larmuseau and other scientists developed other methods to get an unbiased look at cuckoldry.

In a 2013 study, Dr. Larmuseau and his colleagues used Belgium’s detailed birth records to reconstruct large family genealogies reaching back four centuries. Then the scientists tracked down living male descendants and asked to sequence their Y chromosomes.

Y chromosomes are passed down in almost identical form from fathers to sons. Men who are related to the same male ancestor should also share his Y chromosome, providing that some unknown father didn’t introduce his own Y somewhere along the way.

Comparing the chromosomes of living related men, Dr. Larmaseau and his colleagues came up with a cuckoldry rate of less than 1 percent. Similar studies have generally produced the same low results in such countries as Spain, Italy and Germany, as well as agricultural villages in Mali.

Keep in mind, though, that most cultures in the Eurasian world and Islamic North Africa evolved intense social measures to reduce cuckoldry. Mali is on the cultural border between Islamic North Africa and sub-Saharan Africa. I would not suggest generalizing from this one study in Mali to sub-Saharan Africa as a whole without a lot more research.

Also, there may well be a class differential. A study in Mexico found a five time higher rate of paternal misattribution among the lowest class than in the highest class. (The lyrics to A Boy Named Sue might help explain this if it turns out to be a general phenomenon.)

As I wrote in Taki’s Magazine in 2013, however, we need to be careful in kicking percentages around because you’d get different percentages depending upon who gets asked what under different circumstances. Methodologies matter:

A more subtle issue in making sense of the wide range of estimates is the question of “misattributed by whom?” The odds of getting the biological father’s identity wrong are least likely for the mother, next lowest for the presumed father, then the child, and highest among outsiders.

For example, studies based on medical crises where the child’s life is at stake might come up with estimates closer to the mother’s misattribution rate. Pediatric cancer clinics are experienced at making it clear to mothers that they can’t afford to waste time and engage in distracting soap operatics by testing men who only think they are the genetic fathers.

On the other hand, a casual assumption by a child’s, say, schoolteacher of who the student’s genetic father might turn out to be wrong much more often than in, say, a private consultation between a mother and her doctor.

After all, there are a lot of complicated life histories out there:

To get some sense of the potential variety of “non-paternity events,” note that three of the seven most recent presidents went by different surnames at some point in their lives:

Barry Soetoro (Obama), William Blythe III (Clinton), and Leslie King III (Ford).

David Maraniss, the Washington Post editor who wrote the most exhaustive Obama biography, found several Indonesians who had known Obama in Indonesia, including some former in-laws, who more or less believed complicated theories about how Obama could be genetically Indonesian.

[Comment at Unz.com.]