Genetics and sexuality: Why ask why?

The Toronto Star features an article about genetics and gayness. I thought the contrasts between Canada and the US were interesting and the explanations about behavioral genetics enlightening for a lay audience. Discussing Hamer’s early Xq28 research, the article notes the media fascination with the topic:

Because of the social, political, and cultural implications, his results – inevitably headlined “Gay gene found” – were hailed globally as a major breakthrough. Wrongly so, said the genetics community. The coverage was inflated, simplistic and misleading. No “gay gene” had been found, nor ever would be. Why? Because behavioural genetics is much more complex than “Mendelian” genetics. In other words, traits such as eye colour are 100 per cent inheritable but the genetic contribution to various behaviours, aggression, shyness, extroversion and so on, is considerably less, below 50 per cent.

Ruth Hubbard, Harvard emeritus professor of biology and biochemistry and author of Exploding the Gene Myth, has said that searching for a gay gene “is not even a worthwhile pursuit.

“I don’t think there is any single gene that governs any complex human behaviour. There are genetic components in everything we do, and it is foolish to say genes are not involved, but I don’t think they are decisive.”

Behavioral genetics research is going to continue to explode. The fun is going to be in examining pathways for the expression of various traits under various conditions.