Jim Trelease, Cindy Georgis. Guide to Reading Aloud: A reference book for loving parents, caring grandparents and smart educators. (№ 463592)

Young children ask to be read the same book over and over again because it helps them learn language (including story structure). This process is called immersion. Listening to the same book over and over again is part of immersion. Repetition, among other things, promotes mental development: the child hears speech, masters words and concepts, acquires certain speech skills - and the necessary neural connections between brain cells arise and are strengthened.