[Antoninus]

If the brains of gay men and lesbians show differences to straight men and women - that is data.

All kinds of mental illnesses cause differences in the brain. Some are genetic. Many are the result of environmental factors, trauma, or bad habits that the individual developed quite on their own. As such, this data by itself (if accurate) proves exactly the same as would similar data from the brains of people with PTSD.

[scripter]

As such, this data by itself (if accurate) proves exactly the same as would similar data from the brains of people with PTSD.

An excellent point. Another is that behavior causes differences in the brain, but for some reason some scientists apparently decided to forget what we already know to push some bogus causal agent for homosexuality.