There is a critical element missing from the debate, that further complicates things. Importantly, though, it distinguishes humans from animals.
About halfway through gestation in mammals and humans, the testes of a male fetus excrete a small amount of testosterone, which is carried in their blood to their brain. This tells the male fetus’ brain that it should be a “male brain”. If this testosterone is not received, the brain of a fetus is, by default, female.
This process can, and is sometimes interfered with, both naturally and artificially. However, and this is the zinger, in animals, it will determine sexual behavior—but NOT in humans.
In humans, a person will be more masculine or more feminine, based on having a male or female brain, but it will NOT determine who they are sexually attracted to.
If a female animal receives testosterone in its brain, it will try and mate as if it was a male. If a male animal does not receive testosterone in its brain, it will exhibit female mating behavior.
Scientists even tried limiting testosterone to half of an animals brain, and discovered that it exhibits *both* male and female mating behavior.
But in humans, this is not the case. Even if all testosterone is blocked from reaching the brain of a male fetus, while the adult male will be very feminine in their behavior, liking and disliking what females normally like and dislike, the odds are strongly against their being homosexual. That is, even if they are very feminine, they will still have only an ordinary statistical chance of being homosexual.
Conversely, if a female human fetus gets testosterone in her brain, as an adult she will be very much a “tomboy”, but still be strongly sexually attracted to men, outside the usual statistical occurrence of lesbianism.
This was first examined by researchers in the 1960s, then the research was duplicated by the government at a much larger scale in the 1980s. The reason for this was increasing concern that chemicals in the environment could interfere with this process.
For example, farmers frequently use plant estrogen on their crops, both for size and yield. But plant estrogen is similar to human estrogen, and estrogen can interfere with testosterone. So the fear was that using plant estrogen on food crops could result in widespread homosexuality.
Which didn’t happen.
In the final analysis, this research should boost those that believed homosexuality is a social, not exclusively biological development. And if it is a learned social behavior, it might be unlearned.
Very interesting post — thanks.