Although this article makes the Harry Potter comparison , I'm still very interested in the underlying idea that when you read, you"psychologically become part of their world and take away emotional benefits."
Forget wizards, let's talk Shakespeare. Isn't this describing exactly what we've always known Shakespeare to be great at? We love the Henry V speech because *we* take our own personal motivation from it. We get all deep and existential with Hamlet because hey, it's not like we know any more about the undiscovered country than he did, and we're still just as consumed by it.
A fairly obvious question would be, "Doesn't all fiction do this?" and I suppose the answer is "Yes...to an extent." Sometimes to an extent so small that you don't even notice. It takes a master to build universes. Star Trek, Star Wars, Lord of the Rings, and yes even Harry Potter. For every "classic" (forgive me for calling Harry Potter a classic already), there are hundreds of knockoffs and wanna-be's that tried to paint an almost identical universe, and came up short.