This would be true if the only if homosexuality were completely genetically determined. If being gay depends on a particular set of genes and an enviromental trigger, one could miss the enivronmental trigger and turn out straight. But the possibility of turning out gay hinges on having this particular set of genes, not any set of genes. And in this sense there is a biological prerequisite.
> The quicker we get past this goofy nature/nurture debate, the
> better.
>
> Miles
This is not a case of nature or nature, my point here is that you can't nurture just any nature for this behavior, you need a particular nature (set of genes) to start with.