The observed hyperactivity is not independent from, but born of, the impulse control problem. To be ADD is to be hyper-responsive, not hyperactive. Failure to inhibit is at the core of the problem. ADD has an early onset. By this time, 'normal' children are learning self-control.
All young children are impulsive, but they eventually learn control.
ADD children act better in a one to one setting than in groups. They behave better in the presence of fathers than mothers. This is also observed in other children. He suggests that you not try to reason with your children in every situation - ADD is not a failure of reason, neither is it a failure of knowledge. For the person with ADD, novelty is a reward.