Martin Dimond Stewart Braine (June 3, 1926 – April 6, 1996) was a cognitive psychologist known for his research on the development of language and reasoning.

[6] Braine edited the volumes Categories and Processes in Language Acquisition by Yonata Levy and Izchak Schlesinger,[7] and Mental Logic with David O'Brien.

In London he attended lectures by Jean Piaget, which influenced his later research on the development of logical reasoning.

[15] Prior to Noam Chomsky's arguments for innate linguistic universals,[16] there was a strong belief that the structures of language were learned from the input.

Braine offered a compromise position that language acquisition was a process of mapping utterances onto a syntax of thought, supported by semantic primitives and a mental logic.

[17][18] Braine's view that toddlers learn the combinatorial properties of words on an item-by-item basis paved the way for usage-based, lexicalist approaches to grammatical development.