Earlier this year, when The Hunger Games was released as a movie with the attendant interest in the books, there was some media and social media chatter about the popularity of a young adult series with adults. Which is not a new issue: the Harry Potter books, while marketed to young adults, have been very popular amongst adults, as well. This got me thinking, about what exactly the definition of young adult is.
My profession, such as it is, includes being an adult literacy tutor, so I have a professional reason for reading lots of young adult books, which are good for people developing their reading skills. But mostly I just really like reading young adult books. Having read a large variety of them, from the good to the bad to the ugly, I can say a little bit about what all young adult books have in common.
"Young adult" is not a genre. It encompasses many genres. There have been a number of young adult books in the fantasy genre, with the stereotypical plot of "young children fall into a magical kingdom and become heroes", there is also as many young adult books that are typical slice of life stories about real world problems of adolescence. Some young adult books try to impart a message, either subtly or ham-handedly. Some are simply entertaining reads. Some are formulaic, especially the series books. Some are original. Within "young adult", a division is sometimes made between juvenile books written for preteens and books aimed at teenagers.
The truth of the matter is, "young adult" is a marketing label, and there is little else that these books share in common other than the fact that a publisher, bookstore or library has chosen to group them as such. The only requirements for being young adult, from my experience, are a) a writing style that is relatively non-complex, b) no (very) explicit sex or violence. Other than that, you can do whatever you want.
In terms of themes and quality, there is nothing that separates young adult literature from adult literature. That a marketing decision should send a good book to a ghetto where adults will consider it, at best, a "guilty pleasure" is an unfortunate thing.