This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book provides whether children's intelligence can be raised by the intentional actions of parents and other caregivers during the developmental years. It presents evidence and arguments concerning both propositions 1 and 2. The book suggests environmental effects on Intelligence Quotient (IQ) but does not attempt to specify exactly what these environmental effects might be. It shows that very little of the existing gaps can be explained by existing deficiencies in school programs. The book discusses Proposition 4, that the best agent of change for optimizing risk factors and maximizing IQ is the family. It deals with the corollary of Proposition 3 that risk factors operate early in a child's development, and that the ability to change a child's IQ and achievement diminish substantially by the time a child is seven or eight.