(1) So lesbianism has a different cause then. Fair enough.
The cause is likely the same (imbalanced hormone exposure during prenatal development), but the outcome is different. Research indicates that gay men have a feminine brain structure, while lesbians have a masculine one.
Gay men also outnumber lesbians 3:1 which is most likely due to the fact that fetuses start out physically female.
(2) Its not soy, but the feminine hormones at fault. Are you suggesting that brain changes cannot occur to the child after its born. Especially at a very young age when drinking formula?
There is undoubtedly brain development after a child is born, but what I'm alluding to is the fundamental brain pattern. Men and women have different brain patterns, and these brain patterns are formed during prenatal development.
It's these same patterns that researchers found to be "different" in homosexuals, in the sense that they mirror that of the opposite sex, more than the same sex.
(3) It causes an increase. It is not the sole cause. There could very well be other things that cause an excessive amount of female hormones to be in a man.
The power of hormones to create deep changes diminishes greatly over time. For instance, in the womb, testosterone exposure can cause the fetus to develop masculine attributes, ie a penis, testes, brain pattern etc... That's how boys are made.
Give estrogen to a young boy before puberty, and he will be indistinguishable from a real girl, boobs, hips and all unless you pull down his pants.
Give that same estrogen to an adult man however, and he will end up looking more like a cross dresser than anything else. That's because his body has already been masculinized to the full extent, and the power of the female hormones to enact changes is severely diminished.
The part I found the funniest was when they came out with BPA-free bottles because they were worried about estrogen-like horomones leaching out of the plastic into the formula
I think chemicals like BPA or foods like soy that can mimic estrogen may be causing the testosterone levels and sperm count of men to diminish (a long with mineral depletion in the soil) all across the World.
But I don't think they are responsible for homosexuality. Homosexuality goes much deeper, to the genetic level.