Mark Twain Vonnegut is an American pediatrician and memoirist. He is the son of the late writer Kurt Vonnegut, Jr. and his first wife, Jane Cox. He is also the brother of Edith and Nanette Vonnegut. He described himself in the preface to his 1975 book as "a hippie, son of a counterculture hero, B.A. in religion, (with a) genetic disposition to schizophrenia."