From the beginning, Jack thought he should 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 claims he should be the leader. Jack uses mob mentality to get his way:
The space under the palm trees was full of noise and movement. Ralph was on his feet too, shouting for quiet, but no one heard him. All at once the crowd swayed toward the island and was gone – following Jack. (2.120-123)
Jack uses manipulation and control to get the boys to follow his lead. He tries to gain power by giving the boys meat:
“I painted my face – I stole up. Now you eat – all of you – and I –“ (4.191)
Jack reminds Ralph of his own inadequacies. Jack tells Ralph to shut up and Ralph shouts back that he is the leader.
“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)
Clearly, democracy has no value to Jack. He believes in anarchy. He tries to get the boys to join him and abandon any good sense under Ralph's leadership. Jack is blinded by his own ambition. He sees Ralph's leadership as a joke.
Jack tries to get the others to join him in his leadership. He tries to get the others to abandon Ralph's leadership:
“Who thinks Ralph oughtn’t to be chief?”
He looked expectantly at the boys ranged around, who had frozen. Under the palms there was deadly silence.
“Hands up?” said Jack strongly, “whoever wants Ralph not to be chief?”
The silence continued, breathless and heavy and full of shame. Slowly the red drained from Jack’s cheeks, then came back with a painful rush. He licked his lips and turned his head at an angle, so that his gaze avoided the embarrassment of linking with another’s eye.
“How many think –”
His voice trailed off. The hands that held the conch shook. He cleared his throat, and spoke loudly.
“All right then.”
He laid the conch with great care in the grass at his feet. The humiliating tears were running from the corner of each eye.
“I’m not going to play any longer. Not with you.” (8.67-75)
When Jack cannot get his way, he decides he does not desire to play the game any longer.
Later, Jack ties once again to get the boys to follow him:
“Who is going to join my tribe?” (9.52-57)
Jack has become consumed with power. He desires to be sole ruler. He will stop at nothing to get his way.
He is cruel when killing the sow. He slings blood over the boys. He rubs blood on their faces:
He giggled and flecked them while the boys laughed at his reeking palms. Then Jack grabbed Maurice and rubbed the stuff [blood] over his cheeks. (8.195)
Killing has become a game to Jack. He likes to disguise himself with war paint or blood. This is a way to distance himself with the actual torturing of the sow.
Under Jack's leadership, Simon and Piggy die. Ralph would have been next had it not been for the naval officer who rescued the boys.