I've noticed some speculation and muttering lately on these here Internets about categories for kids' books. I thought I'd throw my two pennies into the ring.
When I was a kid, I don't think the categories YA (young adult) or MG (middle grade) existed. There were generally two sizes of books in what was called the Intermediate section of the library. The trade size, which is the larger of the two, indicated (to me, anyway) books for ages 8-12 or so: Beverly Cleary, Eleanor Estes, and the Tales of a 4th Grade Nothing books by Blume. The smaller sized books, called mass market, were in spinner racks. These were for the 12-and-ups. Books like the Sweet Valley High series. SE Hinton. Robert Cormier. More mature works by Judy Blume. There were sub-categories for Fantasy, Science Fiction, Mystery, and Non-fiction.
That was it.
Many kids in high school were assigned books to read such as Huck Finn and To Kill A Mockingbird. These books were found in the Classics section, and included both adult and children's classics. Also, many high schoolers were reading books from the adult section.
Ten years ago, I managed a children's bookstore. We had Picture Books, Early Readers (short, easy chapter books), Intermediate (ages 7-12), and YA (ages 11-14 or so), as well as the usual sub-categories. We determined the correct placement in the store not only by size (mass market vs. trade) but also by content. Some books overlapped.
Today, there are many more categories. That can be a good thing, but it can also make it harder to find the specific book you're looking for in a bookstore or library. Intermediate became Middle Grade, and now there's Tweens as well (ages 10-12).
Also, the Young Adult category has grown fantastically over the past decade or so. It's also gotten edgier. Typical young adult books are considered suitable for ages 10 or 12 to 15 or so, depending on content and the child's reading/comprehension level. You'll find elements including romance (crushes and dating), dysfunction, social/racial/ethnic issues, some abuse (physical and emotional), and sometimes tragedy including death in contemporary YA (for whatever reason, death in historical middle grade appears acceptable, but I don't see a lot of death in the 7-10 year old range of books when the characters are living in current times -- Though Bridge to Terabithia comes to mind).
YA has expanded in age as well, to include more mature themes. Drugs, sex (with some detail, but generally not terribly explicit), moderate amounts of profanity, emotional illness and and teen problems such as anorexia, sexual abuse, teen pregnancy, suicide, murder (as opposed to accidental death)...everything you might find in an adult book. This category is sometimes referred to as Mature YA, Upper YA, or Teen Lit.
So if this upper YA category is similar to adult books, why does it exist? I'm not positive, but unlike 20 years ago, it seems that if the main character of a book is under the age of 20, the book is considered Teen Lit by default.
I invite you to share your opinion -- my post here is my own personal opinion which relies somewhat on memories from 10-30 years ago. I could be waaaaay wrong on this. But I think I'm closer to reality than some.
More on Teen Lit in the next post.