Social Environment in Naturalism
This goes way beyond stereotypes like "If you're from New York you're bitter and wear black" or "If you're from Seattle you totally love coffee, hiking, and being pretentious."
The Naturalists were super interested in exploring social environments. That's because they believed that social environments largely determine our character, and even our destiny. If we're Donald Trump's kids, from a background with loads of money, chances are we're going to do pretty well in life.
On the other hand, if we're born in the slums, raised by parents who have very little money, chances are we're not going to do very well in life. The Naturalists were especially interested in exploring how social environments shape human beings, and how they influence the way they behave. If your first thought is "Dang, that sounds de-pressing," well, Shmooper, you're totally right on the money. It is.
Chew On This
Bigger and his family, the African American protagonists of Native Son, live in a racist world. Because of their social environment, they live in fear. Check out these quotations showing how racism makes Bigger's sister fearful.
Is there any environment more extreme than war? The Civil War, the setting for Stephen Crane's The Red Badge of Courage, is the social environment that Crane explores in his novel. Have a look at an analysis of this environment here.