Children exposed to religion have difficulty distinguishing fact from fiction

A study published in the July issue of Cognitive Science determined that children who are not exposed to religious stories are better able to tell that characters in "fantastical stories" are fictional - whereas children raised in a religious environment even "approach unfamiliar, fantastical stories flexibly."

In "Judgments About Fact and Fiction by Children From Religious and Nonreligious Backgrounds," Kathleen Corriveau, Eva Chen, and Paul Harris demonstrate that children typically have a "sensitivity to the implausible or magical elements in a narrative," and can determine whether the characters in the narrative are real or fictional by references to fantastical elements within the narrative, such as "invisible sails" or "a sword that protects you from danger every time."
However, children raised in households in which religious narratives are frequently encountered do not treat those narratives with the same skepticism. The authors believed that these children would "think of them as akin to fairy tales," judging "the events described in them as implausible or magical and conclude that the protagonists in such narratives are only pretend."
And yet, "this prediction is likely to be wrong," because "with appropriate testimony from adults" in religious households, children "will conceive of the protagonist in such narratives as a real person - even if the narrative includes impossible events."

Well, what did you expect when you teach them fantasy is real?