That Will's games aren't used just for fun, was already known. A new article was now published, which gives an example of how The Sims can be used to make people see how they really live their own lives, and why it's (sometimes) such a mess. Here's a little quote:

"Maybe that's because playing The Sims is almost exactly like coping with everyday suburban life. To begin, you build a home, choosing details down to the pattern of tiles on the kitchen floor and the shape of the backyard pool. Then you help your Sims along as they stumble along through existence."

If you're interested, click here for the whole article. Another old article (from 2001) also has some information on psychology and games, which you can find right here.