Some don't do so well. They have trouble paying attention. Their grades are poor. It may not be a question of I.Q. but of behavior and attitude. Research has shown that these qualities affect success in the classroom.
Successful students behave in certain ways.
And, when they need help with schoolwork, they know how to get it. None of those things are inborn, but they can be learned. And you, as a parent, can help a child learn them. They are for children of all grades. They will sound simple, because they are.