Noting that beyond the individual variations among humans, there is a body of mental abilities common to every human being, this book examines the debate among researchers about the extent to which humans are "preprogrammed," and suggests a new scientific psychology of human development. By examining experimental data obtained from adults, newborns, and animals, the book suggests that while human cognitive capacities are clearly very versatile, they are also very specific. It proposes that like other animals, humans are able to adapt in astonishing ways to new situations and needs, but only in certain areas and within certain limits. Although they can endlessly acquire new knowledge, they do so only within a restricted framework. Although cognitive skills can evolve, they can do so only within the confines of a relatively narrow genetic envelope, which imparts to members of the species a fixed core of aptitudes that everyone possesses. The chapters of the book are as follows: (1) "Explaining Our Behavior"; (2) "Seeing and Hearing"; (3) "The World and Its Objects"; (4) "Self and Others"; (5) "The Biological Foundations of Language"; and (6) "Conclusion: Human Nature and the Cognitive Sciences." (Contains nearly 300 entries.) (AA)