Jack is a boy who it seems is programmed to be violent. He is not good looking and is very unsure of himself. Jack early develops a taste for violence. At first he's a leader of the choir, and then for the hunters. He has this ability to frighten and threaten those under him. Jack is always ready for a fight. On the other side Jack does have some good qualities - bravery and resourcefulness. But these qualities easily get looked over, because of his anger, envy, pride, and lust for blood. And his egotistical outbursts and his temper show that he is immature in his social development. .
It is the problems that Jack causes that bring about the rift between the group of boys. Jack is the savage one, the problem maker. This whole book would have turned out different if Jack had thought more about the group than about himself. If he had thought about the good of the group and what would benefit them all some of the awful things that happened would not have happened. From the start of the novel he does not like following rules of ant kind. He just wants to hunt and have fun and doesn't seem to care about being rescued.
Imagine if Jack had decided to accept Ralph as the leader of the group. He could have taken it upon himself to be a good hunter, and taught others to hunt. He could have also made sure the boys in the choir who were to keep the signal fire going did their job. He could have set an example for the other boys. .
If Jack had done these things they might have not missed signaling the first ship that went by. Even if they had missed that one, life on the island would have been better for everyone. The boys may never have descended into the savagery that ended up killing Simon and Piggy. Jack may actually have ended up being a role model for the younger boys.
