The Fourth "R" (also known as The Brain Machine) is a science fiction novel by American writer George O. Smith, first published in 1959. It is a science fictional examination of the genius naïf phenomemon. The plot follows a five-year-old boy named Jimmy Holden, who was given the equivalent of a college education by virtue of his parents' invention, an "Electromechanical Educator." The book is not related to the movie The Brain Machine (1977).
