What is causing the friction between Ralph and Jack?

Answer 1

There is always an underlying conflict between Ralph and Jack, primarily on Jack's part. Jack has always been use to being in command of his choir and resents the fact that a group of children for whom he holds no regard or respect elected Ralph into a position of power which he coveted. Later as Ralph, aided only by Simon, attempts to build a third shelter for the use of all the boys he shows his own resentment towards Jack when he says... "They work for five minutes and then wander off or go hunting." Implying that while Jack his having fun hunting he is stuck doing routine and thankless but necessary tasks. The division becomes even wider after the signal fire is allowed to go out and Ralph begins to accept that Jack not only wants his position as chief but that Jack actually hates him too.

Answer 2

Ralph and Jack are somewhat jealous of each other. Ralph was the one elected leader, and Jack had once ruled the choir. However, the loyalty to Jack has been stifled because Ralph continues to grow more powerful and more influential. From the beginning, Ralph has been seen as the good leader that the littluns wanted. Jack wants control, but cannot be granted it via democratic processes.