John H. Schumann is an American applied linguist and Professor Emeritus of Applied Linguistics at UCLA. His career moved from a classic SLA starting point — the acquisition data of a single learner — to neurobiology, affect, and the biological substrates of language learning.
Schumann is best known for the Acculturation Model, which argued that an adult learner's acquisition of a second language is constrained by the social and psychological distance between the learner and the target-language community. The model emerged from his longitudinal study of Alberto, a Costa Rican immigrant in Boston, whose English showed features reminiscent of pidginization rather than steady development. Later in his career, Schumann turned to the neurobiology of learning and motivation, work that anticipated much of the current interest in embodied and affective SLA.