I'm not sure why my comment is at -1. People often start out at disadvantage, no matter how rational their character, and no matter what their potential*. You can't expect immediate maturity. I was raised as a fundamentalist Christian. I took it pretty seriously around the age of 14 or so, so much that I started looking into apologetics (the rational defense of the faith). After critically evaluating all the arguments for and against, I ended up abandoning the faith within a couple years. If my parents hadn't gone down the path of fundamentalism (which only started when I was around 8 anyway--before that they were much more average-like Christians) then I probably wouldn't have become an atheist nearly as soon. I find it unlikely that I wouldn't have ended up as a rationalist, though.

* Of course, people who are raised as rationalists have more potential, but potential has more to do with intelligence and disposition than upbringing.