Responding to old post:

In 1966, the Israeli psychologist Georges Tamarin presented, to 1,066 schoolchildren ages 8-14, the Biblical story of Joshua's battle in Jericho:

If you ask a question to schoolchildren, you have to take into consideration that children are supposed to obey authority figures. And not only because the authority figures have power, but because children don't know and can't comprehend many important things about the world, and that makes it a good idea for children to put little weight on their own conclusions and a lot of weight on what authority figures say.

God, of course, is supposed to be an authority on right and wrong. Fundamentally, children thinking "God says that I should kill lots of people so I should, even though I think that is wrong because of X" is no different than children thinking "Mom says that I should look both ways before crossing the street, so I should, even though I think that is wrong because of Y". The child would be wrong in the first case and right in the second, but he'd be following the same policy in both cases, and this policy is generally beneficial even though it fails this one time.