As I have stated before one of the strangest things to me is the ‘urban myth’ among many biologists that 10% of children exhibit misattributed paternity. In plain English, one out of ten fathers of any given child are not their biological fathers, though that is the social understanding. So this excludes children who were adopted and such. In general these are explicitly cases where the putative father is unaware that he’s been cuckolded.
The 10% figure is a nice round number, and I regularly hear it in the public arena, but it is also surprisingly pervasive among academic scientists. A few years ago I was in a seminar where a behavioral ecologist alluded to the figure in passing, and being who I am I had to raise my hand and object that it just wasn’t the true. The researcher, who did not work with humans, was genuinely surprised at my objection, and didn’t seem to be particularly invested in the figure he gave, and was quite open to updating his beliefs about this issue.
More recent work seems to have confirmed this finding: Low historical rates of cuckoldry in a Western European human population traced by Y-chromosome and genealogical data. It seems obvious that a 10% rate of confused paternity is going to show up in a discordance between genetic and genealogical paternal lines.
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