Why does Maurice walk away when Percival starts crying, and why doesn't Roger throw the stones directly at Henry? What does thier behavior suggest about human nature?

oger walks a fine line between the old and new world. He has this urge to hurt things and watch them suffer. We see this in his interactions with the "Littluns". Roger throws rocks at little Henry. Roger aims to miss because the rules from the old world subconsciously stay his arm. Somewhere in his brain lies the memories of adults and reprimand. These memories, however, are fading fast leading Roger to be the true masochist that he is.