You Can Relax: False Paternity Is Way Less Common Than Researchers Originally Thought

Ease up on the mailman.

Originally Published: 

You can be forgiven if you ever watched your kid enjoy an episode of the Teletubies and thought, “This one can’t be mine.” After all, when DNA testing became mainstream in the 90s, a bunch of studies suggested that between 10 and 30 percent of men weren’t their offspring’s biological fathers. That’s a pretty uncomfortable margin of error, but it turns out it’s likely really, really inflated — that’s the conclusion of geneticist Maarten HD Larmuseau, who determined that those study samples were flawed because they’re based on men who had reason to doubt paternity in the first place.

Instead of looking at DNA, Dr. Larmuseau and his colleagues looked at detailed birth records to reconstruct large family genealogies dating back four centuries. Scientists looked at the male descendants and the sequencing of their Y chromosomes, which would match from father to son if there’s no homewrecker in the mix. His 2013 study along with several other studies with differing cultures and methodologies all came up with a false paternity rate of less than one percent. So you might have 99 problems, but being tricked into being a dad is not one of them. That little booger factory coloring the walls is very much yours.


Scientists think that evolution is the reason for the cuckoldry rate being so low (yes, cuckold is a science word too). In another study scientists looked at species where females have multiple male partners and found that their sperm evolved to compete as a result. But your sperm? “It’s of amazingly low quality,” say Dr. Beverly I. Strassmann, who gathered the research. “Half the sperm can be duds; they can have two heads; they can be defective in all sorts of ways.” Ouch, Bev.

What she’s trying to say is that there’s even less reason for you to doubt the paternity of your kid, because even if the missus was messing around, the guy just wasn’t that likely to have a successful shot on goal. So … thanks, Bev?

[H/T] The New York Times

This article was originally published on