Here's a New One

Asexual people are started to get organized and get the word out about their perspective. These folks don't experience a natural sexual attraction at all and have some unique situations to deal with as a result. They are just as capable of getting close to another person, but the whole sex thing is not in the cards.

My own theory about attraction is that it starts with scent. Most of us produce pheromones and most of us react to the pheromones of the opposite sex, the same sex or both sexes. Undoubtedly, there are those that don't react to any pheromones.

Oh, and there is a part of the brain that is smaller in gay men than in straight men. Its right behind the nose, so maybe its connected.