When characters call each other names like Polack ignoramous or hillbilly what literary element is being used?

When characters use derogatory terms like "Polack ignoramus" or "hillbilly," the literary element at play is characterization. This use of names reveals the characters' prejudices, social backgrounds, and attitudes toward one another, helping to define their identities and relationships within the narrative. Additionally, it may also serve as a form of dialogue that reflects broader societal issues, enhancing the thematic depth of the work.