What evidence is there in chapter 4 that the restraints of the children's old way of life are falling away?

The episode with Roger and Maurice kicking down the sandcastles thus signals the disintegration of ordered life on the island, and it foreshadows the end of Ralph's democratic plans. The sandcastles are a miniature civilization on the shore. By destroying the sandcastles, Roger and Maurice not only express an abusive power over the younger boys but indicate their increasing disrespect for civilized order and human institutions. Still, Golding suggests, they have not yet devolved into complete savagery. Maurice, remembering his mother's discipline, feels guilty about kicking sand into Percival's eye, and Roger refrains from throwing a stone at Henry. The implication is that the influences of human society are difficult to erase from the human psyche; they remain internalized even in the absence of rules, and conscience retains its hold. Whatever lessons the boys' past had instilled in them prove critical to maintaining some semblance of peace on the island. Despite the stirrings of anarchy, the boys obey notions of appropriate behavior without any real external authority to determine what they can and cannot do. It is only when the boys completely transgress these civilized norms that they suffer.

Roger gathered a handful of stones and began to throw them. Yet there was a space round Henry, perhaps six yards in diameter, into which he dare not throw. Here, invisible yet strong, was the taboo of the old life. Round the squatting child was the protection of parents and school and policemen and the law.

Jack is the first to seriously overstep the boundaries of civilized society. His attempts to become a successful hunter are in effect attempts to succumb entirely to his animalistic nature. His painted face, reminiscent of some less developed societies, supposedly makes him indistinguishable from the animals of the forest. When Jack finally does kill a pig, as he has intended to do since the beginning of the novel, he fulfills a violent blood-lust that, until then, had remained frustrated. The other hunters share this quality; when they dance and sing about killing the pig, they show that they have succumbed to the thrill of violence. They relish the slaughter, an enjoyment that transcends pride and signifies pure lust. As they cheer on the means by which they mutilate the pig, their painted skin, chanting, and frenzy suggest they have developed their own sub-society, one based on rituals and an almost spiritual worship of blood, violence, and slaughter.

His mind was crowded with memories; memories of the knowledge that had come to them when they closed in on the struggling pig, knowledge that they had outwitted a living thing, imposed their will upon it, taken away its life like a long satisfying drink.

Maurice's impression of the pig during the dance calls attention to the increasingly indistinct line between violence against animals on the island and violence among the boys. Significantly, this chapter contains the first instance of explicit aggression between two boys. Jack, now accustomed to harming others with his recent kill, punches Piggy, who, as Golding reminds us, remains an outsider. The chapter further sets up Piggy as a martyr. He has the most grounded concerns of all the boys, and he offers the reasonable proposal that they construct a sundial, but he is also loathed by the others. Only Ralph, the most mature and grounded of the characters, sympathizes with Piggy and agrees with him that Jack made an egregious error by letting the fire go out. Piggy stands apart from the other boys, for he retains the goal of living in an increasingly civilized society. His hair does not even seem to grow, helping him retain the appearance of a normal English schoolboy while the others grow more disheveled and unkempt.