Read my post above. I believe similarly to you, however, I also believe what moreless is saying about our foods, drugs, environment etc. causing confusion\injury to our children before they are even born.
Selected ubiquitous hormones in our food, medicine, environment (they are now found in water, including bottled and the soil we plant in) = big trouble in terms of future human\animal survival.
Remember the commercials "don't mess with mother nature"? Well we have done gone ahead and messed things up pretty good.
That said, I do believe that in any given society (even if it is pristine) individuals can and will be born with a predisposition one way or the other. That is just the odds…