Which author is associated with the naturalist literary movement in American literature?

The association of Theodore Dreiser with the naturalist movement in American literature is well-founded. Naturalism, which emerged as an extension of realism, focuses on the influence of environment, heredity, and social conditions on human behavior. Dreiser's works, notably "Sister Carrie" and "An American Tragedy," exemplify these themes, portraying characters whose lives are shaped significantly by their circumstances and societal factors beyond their control.

Dreiser's approach to storytelling emphasizes the often harsh realities of life, reflecting a belief that individuals are products of their environment, which is a cornerstone of naturalist philosophy. His focus on flawed characters navigating through challenging situations aligns tightly with the naturalist outlook, making him a key representative of the movement. The other authors listed—Ernest Hemingway, F. Scott Fitzgerald, and Mark Twain—while significant figures in American literature, are better aligned with different literary styles; for instance, Hemingway is associated with modernism, Fitzgerald with the Jazz Age and social commentary, and Twain with humor and regionalism.