[First Amendment]

There are a number of bisexual individuals in society. Those individuals can develop a sexual attraction to members of either sex

Or this: these individuals can INDULGE sexual attractions of varying sorts. And even your use of the word "develop" indicate a chioce.

Of course, what is needed is a lot of hard biological research results. Whenever cadavers are available for autopsy and tissue examination, do analysis of brain structure.

First of all, there's no guarantee that looking at a dead preserved brain will shed light on the behavior and choices of the person who used to inhabit the body. Second, even if all kinds of people who used to practice same sex acts do have some kind of brain difference (which is highly unlikely) there is every chance that the brain difference could have been CAUSED by their same sex behavior.

[punster]

"Second, even if all kinds of people who used to practice same sex acts do have some kind of brain difference (which is highly unlikely) there is every chance that the brain difference could have been CAUSED by their same sex behavior."

Is it? Male homosexuals do not have a significantly different BTSC region in the hypothalamus. XY individuals have a significantly smaller BTSC (p=0.005) than heterosexual males or homosexual males. Reference to research published in Nature.