^very interesting concept. I've heard of kids that would draws colors around all their family portraits and what not. Seems like they could see peoples karma but where eventually told that "people don't have colors around them" and so eventually, like you said, they don't.
btw... The nursey rhyme with the pocket full of posies bit is straight out of the time of the bubonic plaugue. It's common practice for children to grow up reciting at least one death chant.