I first bought this book in 1975, and have bought lots of copies to give to friends and family over the years. Unlike all other books of the time which tell you what to do (each book with different advice), it simply tells you what to expect as the baby develops normally, which is incredibly useful. If I remember rightly, for example, at 11 months typically, a baby will learn to throw things on the floor, and will do it all the time. Just normal development, not naughtiness or any problem. I don't know if there are other similar books now, but the facts haven't changed.