Source on that?
Despite having all human genes mapped, we haven't even found a gene (or set of genes) that influences sexual orientation - let alone fetishes.
It seems impossible for a fetish like AGP to be in-born, because it's based on seeing yourself as a women (i.e through gender norms like wearing dresses or makeup)
As a baby, especially before birth, you simply don't know what males and females are, let alone understanding gender norms.
A(n unborn) baby has no concept of male, female, or how either act within society - so how can they inherently have a fetish for it?
Gender norms aren't inborn, therefore neither can AGP because it needs a society to first tell the invididual what's expected of either gender.
I mean, gender norms themselves are "external stimuli" since they aren't inherent neither, so why would AGP be?
How can something, culture based, be inborn?
How would a baby be interested in wearing dresses and makeup, if the baby doesn't even know what either of those are? And how would that work for other cultures?
If it were inborn, would an English baby (born with AGP) but grows up in Scotland then, not have AGP? (with kilts being for men and all)
It would be like saying a fetish for high heels is inborn; that would obviously be impossible, when high heels are a modern, cultural invention that has no genetic aspect