Which defining moments shape the personality of Jack and Ralph?

This is very much an essay question. This is only a short answer forum. Consider when Jack puts paint/berries on his face. This is a point that finally separates him from his old self and the old world. He is free to be the ruthless leader without being reminded of who he used to be. Ralph is really affected when the ship passes in the horizon. He sees that Jack has left the signal fire out. Ralph finds that the boys are so easily manipulated by Jack that the boys excuse Jack's "error" and expect an apology from Ralph. Ralph realizes just how difficult politics on the island is and how control over the boys is dependent on manipulation.