Naturalism:

A literary movement seeking to depict life as accurately as possible, without artificial distortions of emotion, idealism, and literary convention. The school of thought is a product of post-Darwinian biology in the nineteenth century. It asserts that human beings exist entirely in the order of nature. Human behavior is determined by two kinds of forces, hereditary and environment. The individual's compulsive instincts toward sexuality, hunger, and accumulation of goods are inherited via genetic compulsion and the social and economic forces surrounding his or her upbringing. (Literary Terms and Definitions)