Gay Genes, Revisited; November 1995; Scientific American Magazine; by Horgan; 1 Page(s)

In recent years, two studies published in Science seemed to provide dramatic evidence that male homosexuality has biological underpinnings. In 1991 Simon LeVay, then at the Salk Institute for Biological Studies in San Diego, reported finding subtle but signi ficant differences between the brains of homosexual and heterosexual men. Two years later a group led by Dean H. Hamer of the National Cancer Institute linked male homosexuality to a gene on the X chromosome, which is inherited exclusively from the mother.

Both announcements made headlines worldwide. LeVay and Hamer appeared on talk shows and wrote books. They also co-authored an article published in this magazine in May 1994. But LeVay's finding has yet to be fully replicated by another researcher. As for Hamer, one study has contradicted his results. More disturbingly, he has been charged with research improprieties and is now under investigation by the Federal Office of Research Integrity.