How does Fitzgerald's story "May Day" relate to Naturalism?

Naturalism in literature focuses on depicting life realistically and adheres to an underlying philosophy that suggests people are products of their environments. F. Scott Fitzgerald's novella May Day describes in detail a period of a little more than 24 hours in the lives of young New Yorkers from different walks of life. Fitzgerald's use of detail in May Day captures his characters and the time period exquisitely. The descriptions of the clothes are tell-tale signs of social class and wealth:

"...his visitor’s dark eyes roved nervously around the room, resting for a moment on a great English traveling bag in the corner and on a family of thick silk shirts littered on the chairs amid impressive neckties and soft woolen socks."

By this description readers recognize the possessions of a rich young man. The visitor, on the other hand, "held his coat-sleeves down and worked the frayed shirt-cuffs up till they were out of sight." The visitor is down on his luck. Fitzgerald has a gift for dialogue. The flippant exchanges among the characters quickly reveal social class and education. When Peter Himmel encounters two soldiers hiding at a Yale dance, the following exchange shows the stark differences between Peter and the soldiers, Carrol and Gus.

"'And lastly,' finished Peter, 'will you tell me why, when you are in a building beautifully hung with enormous candelabra, you prefer to spend these evening hours under one anemic electric light?'Rose looked at Key; Key looked at Rose. They laughed; they laughed uproariously; they found it was impossible to look at each other without laughing. But they were not laughing with this man — they were laughing at him. To them a man who talked after this fashion was either raving drunk or raving crazy."

When Philip Dean stops by Gordon and Jewel's table and displays his disgust over Gordon's companion, Jewel's choice of words reveals the difference in social standing. "Let’s us get out of here. This fella's got a mean drunk on."The physical descriptions of the characters add to the great distance between wealth and poverty, education and ignorance.

"Dean was blond, ruddy, and rugged under his thin pajamas. Everything about him radiated fitness and bodily comfort. He smiled frequently, showing large and prominent teeth."

At the other end of the spectrum is Carrol Key, the army soldier:

"...one could stare endlessly at the long, chinless face, the dull, watery eyes, and high cheek-bones, without finding suggestion of either ancestral worth or native resourcefulness."

Fitzgerald uses detail, dialogue, and physical description to forge characters that are simultaneously individuals and representations of their social classes.
It is critical in May Day, however, that the characters are not just products of their environments, but bound by them. Two characters try to leave the confines of their upbringing with little success. The first is George Key, the elder brother of Carrol. When Carrol and Gus approach George, a waiter at the Delmonico, George is not happy to see them. In fact, he worries that Carrol will ask him for money. George has a family and steady job as a waiter. But blood ties prevail, and it isn't long before George hides Carrol and Gus in a cleaning closet and promises to bring them the liquor they've requested. Edith's brother, Henry, also attempts to leave his upbringing by becoming a left-wing journalist. Henry eschews his patrician background to serve the common man only to have his leg broken in a riot incited by a rough crowd of soldiers who consider his egalitarian politics un-American.