I didn't expect these results though since atheism isn't a movement like say secular humanism it's hard to define what they mean. Is this just a way of saying that those who aren't born into a religion tend to join a religion when they get older? I wouldn't be so surprised at that in a religious country such as the US. Being born an atheist no more inoculates you against faith than it grants immunity to measles. I also wonder whether marriage partners have a large sway in the process ( I can think of a few people in my former faith who were marriage converts .) If anything this just reinforces my hope that critical thinking , especially regarding faith, will become a core part of the curriculum. Religion should not be placed in a sacred bubble during school time in order to not offend the pious parent. Faith ( the requirement to believe without evidence) is the key to stupidity and educational establishments are negligent when they do not challenge it at every turn.
I'd be very interested in seeing the figures for those who have been religious, done the homework and concluded there is no supernatural power. I think they would more closely define the definition of atheist ( I suspect non believing children are more likely to be agnostic and have no great preference either way.) Once a person has paid a price intellectually to take a position then I think it is much harder to change. I think it very unlikely that I would become religiously inclined again unless a superior being actually manifests ( and I don't mean in my stomach or in a dream or via a little voice behind my left ear - I can't believe in a God who plays parlour games and who can't even use a phone or a computer or some standard communication method.)
A real being wont be promising 70 virgins, blood sacrifices, resurrection for long disassembled atoms, magic fruit and talking snakes or an imaginary justice system involving being infected with smallpox - they will bring higher technology and actual knowledge about physics, maths, astronomy and biology. Their appearance would elicit a golden age of technological advancement unless they are simply farmers in which case we will suffer an eternal Armageddon.