I think that Ralph and Jack have two completely different personalities. Jack's personality symbolizes savagery and Ralph's symbolizes civilization. Ralph tries to find the most reasonable way to handle problems. Having the least amount of conflict, Ralph tries to have order and think of ways to be productive on the island. His main concern is getting rescued in a sensible way.
Jack on the other hand is all about hunting and acting wild. He is starting to become inhumane. He is so quick to hate on Piggy. All the boys are mean to each other on the island, but Jack is in particularly rude. He is so obsessed with power and everything going how he wants it to go about.
I think further in the book the tension between them two will start to heat up and some major problems will form. Some maybe even including their life safety, or weather they get reduced or not.