Over the last decade, the number of paternity tests taken every year jumped 64 percent, to more than 400,000. That figure counts only a subset of tests — those that are admissible in court and thus require an unbiased tester and a documented chain of possession from test site to lab. Other tests are conducted by men who… buy kits from the Internet or at the corner Rite Aid, swab the inside of their cheeks and that of their putative child’s and mail the samples to a lab. Of course, the men who take the tests already question their paternity, and for about 30 percent of them, their hunch is right. Yet as troubled as many of them might be by that news, they are even more stunned to discover that many judges find it irrelevant. State statutes and case law vary widely, but most judges conclude that these men must continue to raise their children — or at least pay support — no matter what their DNA says.

Full story in The New York Times Magazine.