Therefore, ADD is caused by a neurological defect. Another very flippant argument. There are neurological differences between boys and girls, too. Girls tend to do better at some things and worse at other things than boys. For any increase in ability there is typically an equal decrease in some other ability.
Every adaptation is a tradeoff.
But both brain types are normal. Scientists argued for a long time that women were intellectually inferior, and they used their evidence of neurological differences as an argument. Now the same argument is being used again by the medical community to prove that ADDers are inferior. The increase in creativity and inventiveness which many ADDers have may come at a cost, but that does not make ADD a brain defect, unless of course normal people have a brain defect because they are less creative. If ADD is a temperament, then problems are naturally generated by the standard psychology approach which classifies all behavior problems in terms of mental illness or disorders.