From the beginning, Jack is dangerous and motivated to be the leader:
“I ought to be chief,” said Jack with simple arrogance, “because I’m chapter chorister and head boy. I can sing Csharp.” (1.229-231)
Jack becomes even more dangerous. He will stop at nothing to achieve his goal of becoming the leader of all the boys. He represents evil in the story. He has become power hungry. He is overly ambitious and anyone in his way will be endangered.
In the beginning, Jack has trouble killing his first pig:
Jack, Ralph, and Simon go to explore the island and find a pig trapped in vines. Jack draws his knife, but is unable to actually kill the pig. They vow, however, to kill the pig the next time.
Later in the story, Jack has become vicious in his killing of a pig. He decapitates a sow and hangs the bloody head on a stick. Under Jack's leadership, Roger twists the spear in the rectum of the sow and the sow screams in agony:
"He slowly drives his spear into the anus of the sow, torturing it more than killing it"
Jack and the other hunters laugh when they see where Roger's spear is located. They think it is funny. Jack has lost his good reasoning. His good senses are replaced with chaos, disorder, and evil.
Jack creates the war paint that the boys wear to disguise themselves. Jack has determined that he will become the leader. He threatens the young boys to get them to come under his leadership.
The conflict between Jack and Ralph continues in chapter five. Jack continues to be aggressive and dangerous. He is a destructive force. He threatens Piggy:
He again physically threatens Piggy, foreshadowing the eventual violent conflict between the two boys, and he even manipulates the young boys' fear of monsters and ghosts. During the assembly Jack fully abandons the rules and codes of society. He promotes anarchy among the boys, leading them on a disorganized hunt for an imaginary beast.
Jack uses manipulation and fear to organize his hunters. He tries to get the young boys to give in to his leadership. Jack gains his authority from irrationality and instinctual fear, manipulating the boys into thinking that there may be a dangerous creature that they should hunt. This behavior is dangerous.
When Jack kills a pig, he slings the blood as if it were all fun and games. He and the boys have such a good time killing.
Jack screams at Ralph to shut up and Ralph answers that he was chosen chief:
“And you shut up! Who are you, anyway? Sitting there telling people what to do. You can’t hunt, you can’t sing –”
“I’m chief. I was chosen.”
“Why should choosing make any difference? Just giving orders that don’t make any sense –” (5.238-241)
Jack has clearly abandoned any type of order. He represents anarchy. Democracy has no value for Jack. He is blinded by his own ambition. He does not see any reasoning to Ralph's attempt to create order and government. Jack questions the boys to see who will join him in his uncivilized endeavors:
“Who is going to join my tribe?” (9.52-57)
Jack has named his group his tribe. He is determined to gain full leadership over the boys. When Piggy is killed, Ralph finds himself running for his very life. Jack would have killed Ralph had not the naval officer rescued them.