This study from Boston University goes into the impact of religion and thinking later on in life.
The defence for the "imaginative" nature of religion teaching and it's benefit comes from the US though. So let's have Harry Potter instead of the buybel, koran, etc. to teach creativity.
Religious children are less able to distinguish fantasy from reality because they have been taught from a very early age that fantasy is reality. That's the simple fact of it right there.
I've seen posting on You Tube about this and the resonses were horrific! Some people wanted to claim that the study must have been flawed. It wasn't a valid study. They just knew that the children taught early on about god and the bible would be the best adjusted children. How would that be? It's preposterous!
In 1950 we were all the same and taught things pretty much the same way. If we needed answers that nobody had we went to some authority in due time, or the next day or so. Most people believed that we were "a christian nation" and that god (only our god and not all the others) made and controlled everything. Without a daily news source popping into our homes it was easier to ignore death, wars, suffering, disease, children and others dying, etc. Lack of information made it easier to believe god was in conrol and all was right with the world.
This era had archaeologists carrying shovels in one hand and the bible in the other. By the late 1960's they had stopped believing history had to link with the bible, and what they found did not always fit the known belief. The Vietnam era came along and you had vivid bombing and bloodshed mixed equally with dinner and the nightly news. We tended to ignore the horrors or explain them away.
By the time our current Internet age had fully arrived many church people were very confused. The escalation in world violence (proved by TV news) showed that the end times are upon us, and the things being taught in our schools did not match the bible. Since the bible never changes our christian folk had to do something. In fact, they had to do something because they could not keep up. What better thing to do than to have the bible introduced into our public school systems in some way. They knew this would work because they have all the answers already. The answers are there in the bible. The average christian will argue that evolution isn't proven, dinosaur skeletons are false, the earths strata is false, so are dating methods, etc. and most of the Internet is false and cannot be trusted. Of course, they have their own sites, post info and garbage on them often, and that's all OK.
The problem is those damned atheists! They don't want to believe what we tell them to believe, and they keep coming up with something new all the time. We have all the answers already and can fix it only if we can mix words repeatedly and bring "Intelligent Design" into the classroom. We have to do this, they argue, because the buybull proves everything. Wake up, you stupids! Jesus died for you. I've got the Easter Bunny and him cricified. Eat an egg for your sins. Boy are these people incredibly dumb.
Back to where I came in at. Religious children are less likely to distinguish fantasy from reality because to them fantasy is a reality. It doesn't get more simple than that.