How is Jack presented in Lord of the Flies?

In Lord of the Flies, Jack is portrayed as a jealous, childish bully who completely loses control. From the beginning, Jack is rather full of himself. He's the leader of the choir boys, and because he can sing high C, he believes he should be chief. He is embarrassed and angry when the boys vote for Ralph as chief. His jealousy causes him to break rules and seek to draw boys away from Ralph. He attempts to stage a "coup" by calling for a vote to depose Ralph, but no one agrees with him at that point.
Jack's childishness comes across when, after the vote to overthrow Ralph fails, he says he won't play anymore. He stomps away like a petulant child. However, because he is so childish, his "tribe" offers more benefits to the boys: namely, freedom from responsibility, and the pleasure of the "game" of hunting. At the end of the book, when the naval officer appears, Jack's childishness is emphasized as readers see him through the eyes of an adult. He is described as "a little boy who wore the remains of an extraordinary black cap on his red hair and who carried the remains of a pair of spectacles at his waist."
Jack's jealousy and childishness erupt into bullying. After letting the fire go out, Jack is upset with Ralph but takes out his anger on Piggy, an easy mark. He punches Piggy in the stomach and smacks him in the head, breaking his glasses. Later, he leads the boys in a mock pig hunt where Robert takes the brunt of the boys' pushing. He leads the raid on Ralph's camp to steal Piggy's glasses, beats Wilfred for no reason, and kidnaps Samneric. Ultimately, he loses all control as he seeks to hunt and murder Ralph.
Jack is a boy with common boyish faults—jealousy, immaturity, and bullying—who totally loses control of himself in the absence of any restraint from higher authority.