Well, children have certainly had less time experiencing the binding, conditioning aspects of the the world that seems to have pulled us all away from a path of naturally progressing spirituality. They live in a more mutable world where not so much is taken for granted as being fixed and true the way adults, even adolescents, see things.

There is some talk relating this kind of notion to the other planes, other dimensions of reality. They are out there, are brains can easily see and make sense of them, we have just been so conditioned by each other that we have filtered them out, like living next to traffic or something. Once you realize that the traffic, which could actually be extremely important to the functioning of the greater world, has no real meaning for you personally, you stop responding to it and eventually stop perceiving it all together.

So, I think something along those lines is what you're getting at in terms of children being closer to the spiritual. But the fact that you are concerned with the question of bullies, unformed morality and the spontaneous (or like Vee says, obviously derivative from trauma) generation of evil acts in children leads me to a point made by Ken Wilbur somewhere along one of his integral theory discourses.

We are very able to idealize the state of children because it seems better, simpler, more complete than the fragmented, chaotic, often depressing world adults live in. Many might argue that the world of a child is trans-rational and pure. But that does not mean we should regress towards being children, a trans-rational mindset and world view that is much more potent can be achieved by using, knowing, and moving beyond the rational in favor of an evolution, not a devolution.

Moving beyond the rational, instead of moving backwards from it, we can reach a place where we are less conditioned and more spiritually attuned like children, but not through mere ignorance. We can empathize with others, and thus do not bully them. Children, however untainted by the world, still lack the development of critical capacities needed for functioning human communities, such as (depending on the age we're talking) being able to distinguish themselves as one and the world as another (possibly a fallacy), knowing the difference between them and another person (again maybe not actually the case), empathy, abstract thinking...and this is where the distinction between pre- and post/trans-rational comes in. I doubt Buddhist monks or Hindu yogis would revel in the enlightened state of a child, because the child fails to make distinctions between self/not self because of ignorance, not because he/she actually knows anything.

But, maybe not.