Banning cousin marriages makes about as much sense, critics argue, as trying to ban childbearing by older women.
But the nature of cousin marriage is far more surprising than recent publicity has suggested.
Each of us carries an unknown number of genesan individual typically has between five and sevencapable of killing our children or grandchildren.
These so-called lethal recessives are associated with diseases like cystic fibrosis and sickle-cell anemia.
This phobia is distinctly American, a heritage of early evolutionists with misguided notions about the upward march of human societies.
"You get babies with nine heads." So when a team of scientists led by Robin L.
Bennett, a genetic counselor at the University of Washington and the president of the National Society of Genetic Counselors, announced that cousin marriages are not significantly riskier than any other marriage, it made the front page of The New York Times.
Their fear was that cousin marriages would cause us to breed our way back to frontier savageryor worse.
"You can't marry your first cousin," a character declares in the 1982 play Brighton Beach Memoirs.