Quote Originally Posted by Ironside View Post
Unless you're going to argue that over 50% are secretly gay, then it still has a significant biological factor.

Similar to left handedness (or right handedness) that's totally a concious choise... 2 left handed parents still only got less than 50% of their children being left handed, far from 100%, but much higher than the population average. Having one laft handed and one right handed identical twin is not that uncommon, way more common that having 2 left handed one for example.
Sorry?

No, identical twins are identical in felhandedness - "mirror twins" occur when the egg splits slightly later, and they mirror in everything, right down to moles and rogue eyebrow hairs/crooked teeth. Nobody actuall knows what causes people to favour one hand over another, one theory is that every left-hander is a surviving twin.

Different process.

If the genetic factors were deterministic, i.e. if it "caused gayness" then you would expect a much higher correlation