John Hartigan examines the rhetorical maze of racial discourse in contemporary American culture. His work stems from the idea of how "race" is used similarly on plants and people (such as, races of corn). Just as “indigenous” first referred to plants and later to people, so too has the concept of race shifted historically from applying to nonhumans and then humans. Hartigan analyzes how breeders, horticulturalists, and geneticists posit forms of parallels between humans and maize, in order to develop a new analytical perspective on racial thinking broadly.

His research interests include anthropology of science (comparative study of genomics research in the United States and Mexico); ethnography of race (theories, methods, and practice, with an attention to cultural articulations of whiteness); American culture (class and racial discourses, along with questions of cultural form in the U.S. public sphere).