Naturalism is the belief that humans are animals, with animal thoughts and instincts. In John Steinbeck's of Mice and Men, there are many instances where naturalism is used. The characters, especially Lennie, are compared to animals frequently. Many of the characters also have primitive, unfeeling attitudes. The animalistic qualities of Steinbeck's characters show the naturalistic attitude of the book.
Throughout the book characters are compared to animals. Lennie is compared the most often. "Snorting into the water like a horse.", (pg. 3) "The way a bear drags his paws.", (pg.2), "Lennie covered his face with huge paws and bleated with terror," (pg.63)-- all of those things show Lennie as an animal. Curley, too, is compared to an animal -- "Curley was flopping like a fish on a line." (pg. 63). Steinbeck's comparison of these people to animals gives them a raw, rough quality .
The characters are also constantly shown as being heartless and uncaring.
For example, Carlson cruelly demanded that Candy kill the dog, not understanding that the dog was a friend to Candy, and that Candy loved him. "Let's get it over with. We can't sleep with him stinkin' around in here." ,(pg.47) Carlson says, which showed that he was more concerned with the smell than he was with killing the old man's best friend. Carlson also shows how unemotional and insensitive he is when the men find that George killed Lennie. He doesn't seem to understand that this was a man that just killed his friend. "Now the hell ya suppose is eatin' them two guys?" (pg.107) Carlson is clueless to what George is feeling. Curley, also, has a very insensitive attitude. When the men find Curley's wife dead, Curley seems to want to kill Lennie not to avenge his wife, but just because...