The Englishmen
Quote 1
What the Englishman said about survival was this: "If you stop taking pride in your appearance, you will very soon die." He said that he had seen several men die in the following way: "They ceased to stand up straight, then ceased to shave or wash, then ceased to get out of bed, then ceased to talk, then died." (6.13.1)
The narrator specifies several times that Billy has a straggly beard for much of his time as a POW—and yet he lives. Of course, he is not exactly the Englishman's model soldier. Perhaps a soldier of the English officer's kind would die from lack of self-respect, but Billy doesn't seem to have had much self-respect to start with.