There have been several hints that people talk about Darl or look upon him as different. Anse seems to be aware that Darl is also different and views his constant laughter as a sign of Darl's strangeness.
An important question to the total interpretation of the novel is, Why does Darl laugh? We, the readers, have become very familiar with Darl as the sensitive and perceptive narrator. We must then try to create for ourselves the same scene that Darl observes. This scene would involve a pregnant, barefoot girl in a wagon, an ineffectual father murmuring clichés, a young and perhaps retarded brother, a half-crippled brother, the coffin of his dead mother, and then suddenly over the hill the other brother riding a half-wild horse.
Consequently, it can be maintained that this is a rather ridiculous situation and that Darl laughs because he is intelligent and perceptive enough to recognize the absurdity of the entire situation. Or perhaps Darl laughs because he begins to understand why Addie wanted to be buried in Jefferson, a reason that does not become clear to the reader until a much later section. And finally, perhaps this is an indication of a certain degree of madness on Darl's part. Perhaps, then, Faulkner is preparing us for the later scene when Darl will be violently attacked, tied up, and sent off to the insane asylum.
