Best anyone can tell, Eleanor Amrhein and Donald W. Andrews Sr. can blame their sudden quasi-celebrity on rocker-turned-pariah Jerry Lee Lewis.

When Lewis married his 13-year-old cousin in 1958, America thereafter soured on the idea of "kissing cousins," and people like Amrhein and Andrews -- first cousins from the Altoona area who tried, but failed, to get a Pennsylvania marriage license last month -- have had a rough time of beating the taboo.

Before the Lewis scandal, due as much to the young wife's age as the pair's shared genes, America mostly turned a blind eye to cousins who married, and in fact many of us who can trace our lineage back far enough will find a "consanguineal" couple or two. The rest of the civilized world doesn't seem to care, either. Charles Darwin married his first cousin, Emma Wedgwood, and spawned 10 kids, four of them scientists, as supporters of "cousin couples" like to point out. Albert Einstein's second wife was, in fact, his first cousin, and Einstein's no dummy.

Post-war America, it seems, is unique in its societal disdain for cousins who marry. In Europe, the Middle East and elsewhere, the marriage of first cousins is more common and less profane.

"Traditionally, it's been very common in England and Europe, among royalty, to intermarry. Maybe it has to do with royalty doing it -- if they do it, it's OK," said Johanna Garfield, the New York City author who wrote "Cousins: A Unique and Powerful Bond." Even in America, "there was a time when it was much more common. Wealthy families often encouraged their kids to marry their cousins -- not always first cousins, but close enough to keep their money in the family."

While The Killer helped to give kissing cousins their modern social stigma, Darwin himself, and the genetic pioneers that followed him, helped to give consanguineal couples their medical stain, starting in the early 1900s. For many years, it was an accepted truism that first cousins who married were likely to pass genetic defects onto their children. What we had here, people thought, was a game of Russian roulette.

While the taboo has social and medical elements, it is largely religion-free. The Bible doesn't appear to forbid first cousins from marrying, though certain passages of Leviticus forbid marriages among many other relatives. Some religions and Christian denominations don't outlaw the marriages, but discourage them, or at least urge special caution. Eastern religions have fewer qualms.

The result of the American taboo is that 24 states, mostly in the north, have approved laws over the decades outlawing the marriage of first cousins, primarily using the gene pool rationale. The remaining 26 states, as well as Washington, D.C, allow first cousins to marry -- some prescribe qualifying circumstances to the unions, such as age limits or the requirement that the couple does not have children. Other states allow the unions outright, with no qualifiers attached. All states allow marriage of second cousins or more-distant relatives.

Pennsylvania is one of the 24. So when Amrhein, 46, and Andrews, 39, sought a marriage license in Blair County, they were rebuffed. They then traveled to Maryland, where the unions are legal, and were married last week in a civil ceremony. In the process, they earned snickers from Tonight Show host Jay Leno and countless others, thanks to the wonders of Web logging and Internet connectivity.

They don't seem to mind it. "Everybody thought I should be ashamed of it," Amrhein said in an Associated Press story. "I am not." Her new husband, and lover of several years, feels the same. "You can't control who you fall in love with," he said.

Pennsylvania's law forbids not only the marriage of first cousins, but also forbids people to marry their mothers, fathers, daughters, sons, aunts, uncles, grandchildren or siblings.

The latter legal constraints don't create much controversy, because few people want to marry their parents or siblings in the first place. But enough men and women want to marry a first cousin that "cousin couple" Web sites, support groups and lobbying organizations have popped up over the years.

All of them have been bolstered by a 3-year-old report from the Journal of Genetic Counseling, which said that otherwise healthy first cousins are at no great risk of passing chance birth defects onto their children. "Normal" parents have a 3 to 4 percent chance of bearing a child with a serious birth defect, while first cousins have a 5 to 7 percent chance, according to the study, which compiled statistics on thousands of births over a 35-year period.

The researchers concluded that there's a slight risk increase to offspring -- in fact, it more or less doubles -- but because the base percentage is so small, the increased risks aren't so high that cousins ought not be allowed to marry. There's a far better chance, for example, that a person with Huntington's disease will pass the neurological disorder onto kids, yet there's no law forbidding people with certain diseases from marrying.

"It's my opinion that it's a form of genetic discrimination," said Robin Bennett, former president of the National Society of Genetic Counselors. She now teachers at the at University of Washington's genetics clinic.

"You'll note there's nothing in the law that says they can't have children. It's just that they can't marry, which is silly," she said.

Some geneticists still aren't convinced, noting that a 100 percent increase in the chances of passing on a birth defect is quite large, percentage-wise, even if the original odds were tiny. Cousins who want to marry should still be counseled before having kids, to see if they have any damaging, recessive traits that could be passed on.