This is a most unusual book with profound social, political, and philosophical implications that will inform the national debate on intelligence. It combines personality, temperament, and intelligence in a common theory that demonstrates the fundamental psychological and social significance of human differences in brain function. Dr. Robinson goes from cell to psyche in a manner that will appeal to all who wish to know more about the interrelation of brain, mind, and behavior. The book is a well of facts and insights; it provides a sound basis for teaching and a powerful stimulus for research.