Its hard to say that it is only emotional as choosing to become transgender is a horrible choice one wouldn't do easily. But, if indeed these people feel these strongly, then may be it is biological, but not natural. What is vaccines, toxins in the air, pesticides etc... are actually causing a biological mix message. Vaccines use embrio's DNA...??? Could that be a cause? Or perhaps the way vaccines cause autoimmune disease, they may cause the cells going against one's own gender? Just thinking out loud here.