Which “leadership” role on the island does Jack settle into, and what does this indicate about his character?

Jack Merridew is the leader of a boys' choir, Jack exemplifies militarism as it borders on authoritarianism. He is cruel and sadistic, preoccupied with hunting and killing pigs. His sadism intensifies throughout the novel, and he eventually turns cruelly on the other boys. Jack feigns an interest in the rules of order established on the island, but only if they allow him to inflict punishment. Jack represents anarchy. His rejection of Ralph's imposed order--and the bloody results of this act--indicate the danger inherent in an anarchic system based only on self-interest.