Why does Jack hate Ralph?

On the surface Jack hates Ralph because Ralph was picked as chief. I think that on a deeper level Jack really doesn't understand his anger against Ralph. Jack lives in his hate and anger: he lacks the self-awareness to really understand his motivations. In Chapter 7 Ralph asks this very question of Jack. Ralph asks Jack this simple question and Jack can't answer. Aside from the obvious power struggle Jack doesn't really know why he hates Ralph. Jack is unable to understand his rage. As Jack loses himself in anger, his depth of understanding becomes less and less. Jack's need to be in control spills over into the sadistic. Jack understands this the least of any of the boys.