“You see all these ads, so much marketing from the DNA industry, showing that this is a happy, joyous occasion when your results come in, but there’s this other side,” said investigative journalist Samuel Burke in a recent CNN/PBS interview with Christiane Amanpour. “Eleven percent of people who take a DNA test find out that one of their parents isn’t their biological parent. And that seemed ridiculous to me when I heard that number, until it happened twice in my own family.”
To be clear, that 11% statistic is tough to substantiate. The International Society of Genetic Genealogy Wiki paints a more complex picture. In an examination of “non-paternity event” rates (don’t get me started on that terminology) from 67 published studies, rates for populations with “high paternity confidence” ranged from 1.9% to 2.9%. When paternity was in dispute or the confidence level was otherwise low, the rates were notably higher: 29–30%. In the article from which this summary was derived, the author noted that “Nonpaternity rates in human societies are often cited as being 10% or greater in general populations (e.g. Alfred 2002; Cervino and Hill 2000; Stewart 1989), though little or no empirical support is generally provided for this assertion.”
But don’t let all this statistical noise distract you. That’s how statistics fail us. They’re useful when examining large populations with a sufficiently large sample size and sufficiently focused purposes, but when it comes to you and me and our personal experiences, they are utterly meaningless. If you just discovered your mother is not your biological mother (an experience not even touched upon in the studies referenced above), knowing the percentage of people who have made similar discoveries will tell you nothing about what to do with your new information, how to process it, or what to say if you ever meet your biological mother face-to-face. When it happens to you, a full 100% of you is affected, and that is the only statistic that matters. Burke discovered this first-hand.
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