Every time one of America’s genetic-testing companies advertises a deal on DNA kits, Michael (not his real name) braces himself for what may follow: a message from one of his hitherto unknown offspring. Three decades ago, as a student at the University of Houston, Michael became a sperm donor; the clinic would “pull me out of retirement”, he says, every time a customer wanted to expand their family. So far, the 55-year-old knows of around 60 children (and a dozen grandchildren) he has sired in addition to the four teenagers he shares with his wife; he suspects the true number is closer to 100.
“I could write a book,” he says, about the lifelong consequences of what had seemed, at the time, like an easy buck and an incentive to live healthily (he steered clear of heavy drinking and drugs to preserve his sperm's motility). Several children contact him regularly. He has been surprised by how many had been led to believe the father who brought them up was their biological parent: “Sometimes they’re very angry they’ve been lied to... see more