The 2 main things I watch for is: 1. They want to learn to fly planes. 2. They don't talk like > " wouldn't be cool to see the planes crash!!! < don't laugh, I have heard a few kids talk like this!! Indicates an immature attitude and no way is this little person ready to try to fly planes. I have taught as young as 8 years old and thought that that age was very close to the limit as far as concentration levels and being able to listen to instructions while keeping an eye on the plane. [8D]