I was perusing blogs again today and came across a most excellent quote from Dr. Marc Breedlove, Barnett Rosenberg Professor of Neuroscience at Michigan State University. He is currently sponsoring a lecture series called, Whom You Love: The Biology of Sexual Orientation, which is featuring the nation’s top researchers who have studied the science of sexual orientation. Anti-LGBTQ pundits like to talk about how there is “no gay gene,” but aside from us not even knowing how many genes there are or what they all do, it’s probably not as simple as “a” gay gene. According to Dr. Breedlove:

As to the question to whether there is a gay gene, it depends on what you mean by that. Have we found a gene, where when a person inherits it, they will for certain be gay? No, we haven’t found such a gene. There may or may not be one. But we do know there is a gene on the X chromosome that has been proven to have an influence on sexual orientation in men. What’s more, we know there are many genes that influence sexual orientation in people. Probably not just one, but a lot. And it will probably be the sort of situation where whether or not you are gay depends on whether which particular combination of genes you get.

The example I like to use is to talk about height. The estimates are there are 150 different genes that influence height. So, is there a gene for being tall?…No…but does that mean there is no genetic influence for height? Of course not, that would be silly. Of course there is a genetic influence on height. Of course there is a genetic influence on sexual orientation. The data are really completely firm.”

Along with the genetic influences there is strong evidence that prenatal testosterone and fraternal birth order play some role in influencing sexual orientation, most probably by the prenatal hormones activating or deactivating certain genes.

Of course, no discussion on this topic is complete without Lady Gaga’s Born This Way music video: (FYI if you haven’t seen it yet, it’s kind of insane, and graphic)