In the beginning of the story, Ralph really appears to have some idea of what he needs to do to lead the boys. he is elected as their leader, sets up some sort of system where people have a voice, etc. He is really happy for the role, but he also begins to demonstrate some of the weaknesses that will really haunt him later.
By the middle of chapter eight, Ralph has become disillusioned about the fact that he is no longer really the leader and Jack has taken over control. He tries to assert a moral superiority by suggesting that he really cares whereas so many of the boys don't. Piggy helps maintain this illusion as he knows no one else really values his contributions.