Q. Why haven’t you addressed the gay gene in your Q&As? Has no one asked that question, or are you just avoiding it?

A. Since you asked a question about the “gay gene,” so-called, I know of no definitive research that has identified a specific gay gene. In the early 1990s there were studies done looking for X chromosome linkages. Researchers reportedly used twenty-two markers on the X chromosome to test for similar alleles (any of several forms of a gene, usually arising through mutation, responsible for hereditary variation). Similarities revolved around a marker known as Xq28, which was quickly dubbed by some as the “gay gene.” This notion still persists in some quarters. That is not to say a gay gene will not be found. It just hasn’t been found definitively—yet.