The doctors I worked with were at the Cornell School of Medicine in New York City and the work was in papers not in books. There is a general reluctance among medical scientists to say what causes sexual orientation, either hetero or homo. There appears to be no reluctance to say that it is not something people choose, it is a reality to which they awaken. There seems to be some physical link though it does not appear to follow any genetic rules. Yet when I address a large group of say 1000 gay and lesbian people, I know by sight that there is a higher instance of physiological differences among the members of this group that would not be as readily visible in a group of 1000 heterosexual people. However, no one can judge an individual's sexual orientation on the basis of visual data because stereotypes do not hold. Masculine appearing women and effeminate appearing men can be quite heterosexual; and feminine, delicate women and athletic, muscular men can be homosexual. I know no medical scientist who thinks sexual orientation is a volitional decision. If that cannot be demonstrated, the whole argument against gay people falls apart. I find it interesting that most heterosexual people cannot remember when they chose to be heterosexual. That is because they did not choose, they awakened to their identity. Yet in a rather irrational fashion they still think that homosexual people choose to be homosexual. When we talk of "sexual preference," we assume the prejudice that is so deep in our culture.

When seeking explanations, the Cornell doctor who guided my study talked not of a genetic connection but of a neuro-chemical connection. They believed it was somehow linked to the amount of testosterone present in the mother's bloodstream at the moment the brain of the fetus was sexed with its identity, both of which are quite random. They dismissed out of hand environmental influences and considered that argument to be patently ignorant.

I hope this helps.

-- John Shelby Spong