Your information is badly out of date. Studies have been consistently showing biology beating culture for the last 20 years.
For a recent lay presentation on this topic, see http://freethoughtblogs.com/lousycanuck/2014/02/03/ftbcon2-e... . At the top is a link to a Google document ( https://docs.google.com/document/d/1slJbQpPTlg_m6cKgsarzGLqY... ) with full citations.
They talk about male babies who were sexually reassigned at birth and given female hormones. However many of them decided to reidentify as males later on life, showing that even with female hormones and a female upbringing, it was not enough to make them adopt a female gender identity.
I wouldn't say this is conclusive evidence. But I think it's enough to show that people should keep an open mind about this subject.
I'm learning about this now. Shocking. This could pass as some story about medical experiments during nazy germany.
And even if they do happen to agree with actual good science, the few studies presented here still don't "explain" anything and this Live Science post is decidedly shonky science reporting (and calling it that is frankly generous).