In chapter one of Lord of the Flies, how does Golding's diction reveal a theme of contrasting civilization with savagery?

There are various ways that Golding establishes a dichotomy between civilization and savagery since, indeed, that is one of the novel’s major themes. That theme becomes apparent from the very outset, as chapter one immediately describes how the boys are stranded on the island. To clearly identify this theme, we must examine the specific language Golding uses to describe the behavior of Ralph and Piggy as they become aware of their circumstances.
In the novel’s opening lines, Golding places special emphasis on clothing and dress to establish the difference between proper and improper behavior. Ralph has “taken off his school sweater and trailed it now from one hand, his grey shirt stuck to him and his hair was plastered to his forehead.” Ralph has removed his school uniform, effectively casting off the proper dress of a student, so that it “trailed” behind him. Thus, school -- with all its rules and boundaries -- is now in his past, a part of a civilized society that Ralph discards so that he might live like a person with uncombed hair “plastered to his forehead.” Yet the habits of proper dress and behavior are not so easily forgotten, as a few lines later we are told that Ralph “jerked his stockings with an automatic gesture that made the jungle seem for a moment like the Home Counties.” By describing this mannerism as an “automatic gesture,” Golding shows that dressing is a conditioned behavior that is out of place in the jungle, emphasizing the difference between the wilderness and the “Home Counties.”
This is not the only time when clothing reveals the difference between wild and civilized behavior. Later in the chapter, Ralph becomes “conscious of the weight of clothes …” and the accompanying social obligations with being dressed. Thus, he removes all his clothing in a wild manner: he “kicked his shoes off fiercely and ripped off each stocking with its elastic garter in a single movement.” Ralph does not just willingly remove his clothes, he “ripped” them off, “fiercely.” Thus, Ralph undresses with savage-like behavior and excitement; however, after swimming, his dressing is described as follows: “to put on a grey shirt once more was strangely pleasing.” The pleasure of putting his clothes back on indicates that Ralph’s savage behavior, though temporarily enjoyable, cannot completely remove his desire for civilization, a desire that has been instilled in him and that continues to affect him as the novel proceeds.
The mixed benefits of being removed from civilization are further reflected in Ralph and Piggy’s conversations during the first chapter. When Ralph tells Piggy that he does not believe there are any adults, he “said this solemnly; but then the delight of a realized ambition overcame him.” Without any adults, Ralph realizes with “delight” that he is free to do as he pleases since no one can enforce rules or social obligations upon him, which includes not bothering to learn Piggy’s name. Piggy is bothered that Ralph does not do the socially polite thing and ask for his name, which forces Piggy into admitting to Ralph that the kids at school made fun of him. When learning this, “Ralph shrieked with laughter.” The fact that Ralph “shrieked” is a very wild way of laughing, one that would hardly be acceptable in polite society; however, at this point Golding very cleverly inverts our definition of what is civilized: he points out that taunting and name-calling are often common practices at schools. Thus, we are forced to admit that children often indulge in savage behavior and that our very nature is one of cruelty. The reader is forced to consider that we might all behave like savage children if there were no social institutions.
Thus, the difference between civilization and savagery may actually be only a very slight difference, one that does not even exist in a natural state. By looking at specific descriptions of such behavior in the first chapter, we can see how Golding immediately challenges the concept of civilization, which assists him in establishing his major theme of social breakdown throughout the rest of the novel.