Let me say it straightforwardly: Fifty percent of American marriages are not ending in divorce. It's fiction. A humor12-myth. A tragically discouraging urban legend. If there's no credible evidence that half of American marriages will end up in divorce court, where did that belief originate?

Demographers say there was increased focus on divorce rates during the 1970s when the number of divorces rose, partly as a result of no-fault divorce. Divorces peaked in 1979 and articles started appearing that claimed 50 percent of American marriages were ending in divorce.

A spokesperson for the U.S. National Center for Health Statistics told me that the rumor appears to have originated from a misreading of the facts. It was true, he said, if you looked at all the marriages and divorces within a single year, you'd find that there were twice as many marriages as divorces. In 1981, for example, there were 2.4 million marriages and 1.2 million divorces. At first glance, that would seem like a 50-percent divorce rate.

Virtually none of those divorces were among the people who had married during that year, however, and the statistic failed to take into account the 54 million marriages that already existed, the majority of which would not see divorce.

Another source for the 50-percent figure could be those who were trying to predict the future of divorce. Based on known divorce records, they projected that 50 percent of newly married young people would divorce. University of Chicago sociologist and researcher Linda Waite told USA Today that the 50-percent divorce stats were based more on assumptions than facts.

Some researchers have relied on surveys rather than government statistics. In his book Inside America in 1984, pollster Louis Harris said that only about 11 or 12 percent of people who had ever been married had ever been divorced. Researcher George Barna's most recent survey of Americans in 2001 estimates that 34 percent of those who have ever been married have ever been divorced.