weak said:
I don't think it's something you're born with, just like I dont believe people are "born gay". Experiences are what shape us. My SA is just the result of having some really bad experiences as a kid.
Just because I'm really tired of hearing all my life that I must've had bad childhood experiences (heck, teachers always wanted to know if I was being abused), and we need some balance with people from the other side refusing to admit that anyone not like us exists no matter how many testimonials we hear, I hereby deny that it's possible to have non-genetic social anxiety.
A normal person would've dealt with all your bad experiences in a very different way, like a life of crime for example, while remaining social. You have a genetic predisposition to crawl into your shell when you encounter troubles. Many genetic diseases have a delayed onset, and experiences can trigger the specific time of arrival, but the important point is that you were born with the time bomb and it was destined to go off eventually. You are a product of your genetics, period, and even with the most pampered life something would've eventually triggered your social anxiety.
It's also worth mentioning that what a lot of people with SA call a bad childhood experience is what the rest of the world calls perfectly normal. Most kids are bullied, but they don't have your reaction to it. The fact that you call your childhood bad is a result of SA, not the cause.