What does roleplaying games like d&d, computer games, playing baseball, driving fast cars, drawing, tv, climbing, swimming, running, boxing, stamp collecting all have in common? All of them are preferences. Some people enjoy doing them, some people do not. Do I need proof and scientific studies to prove that they are all not genetically build in? If I claim they are preferences, you going to call me illogical, because I couldn't possibly know that a person have a choice. You going to argue with me over how each must be a genetic preference that was built in when I was born?

How come being gay is singled out from all of them, as different. How come being gay needs studies and genetic testing to find out where it comes from, while no such things exist for people who enjoy reading comic books?

The truth is that they are no different. The reason being gay is singled out, is because it involves sex. Not only sex, but a sexual taboo. If it didn't involve sex, we wouldn't think twice about it.

You havn't show any evidence to prove that it is any different from any other preference. Except a vague reference that some scientist, may have discovered a gene that plays a small part in it.