When we talk about intelligence, we do not mean the ability to get good scores on certain kinds of tests or even the ability to do well in school. By intelligence we mean a way of living and behaving, especially in a new or upsetting situation. If we want to test intelligence,we need to find out how a person acts instead of how much he knows what to do.
For instance, when in a new situation, an intelligent person thinks about the situation, not about himself or what might happen to him. He tries to find out all he can, and then he acts immediately and tries to do something about it. He probably isn't sure how it will all work out, but at least he tries. And if he cannot make things work out right, he doesn't feel ashamed that he failed, he just tries to learn from his mistakes. An intelligent person, even if he is very young, has a special outlook on life and a special feeling about life.
If you look at children, you'll see great differences between what we call "bright" children and "not bright" children. They are actually two different kinds of people, not just the same kind with different amounts of intelligence. For example, the bright child really wants to find out about life -- he tried to get in touch with everything around him. But the unintelligent child keeps more to himself and his own dreamworld; he seems to have a wall between him and life in general.