A classification of natal influences is proposed with a model of their operation. Natal influences affect maternal capacity, maternal load, and maternal efficiency. Since maternal load is increased in twin pregnancy, results of twin studies must be generalized with caution. The method of co-twin control is exemplified by examination of a small…

Contents of this book include: an introductory preface by C. Loring Brace; "Introduction to Jensenism," C. Loring Brace; "Can we and should we study race differences?" Arthur R. Jensen; "Intelligence in Black and White," Alexander Alland, Jr.; "Whose is the failure?" Vera John; "The influence of…

"The Bell Curve" by Richard J. Herrnstein and Charles Murray has generated enormous debate as a result of its claim that there is a connection between race and intelligence. The essays of this collection respond to "The Bell Curve" in various ways. Taken together, the following offer an antidote to a work of dubious premises…

It has been said that the heritability of learning ability or of intelligence is irrelevant to teachability. In support of this statement we see it pointed out that a child or a group of children show some response to training, and this is held up as evidence against the heritability of intelligence or learning ability. Most estimates of the…