Much of the work on intellectual development separates development into two separate developmental periods: the formation of intelligence and basic cognitive skills that occurs until adolescence, and the maintenance, decline, or improvement of these intellectual skills across the adult life span. The separation has resulted in what may be artificial development during childhood and adulthood. Intellectual Development seeks to reconnect development by encompassing theoretical issues of intellectual development across the life course. Additionally, Intellectual Development explores the great diversity that currently exists in the types of theoretical perspectives that guide thinking about how intelligence develops through the life course. Robert Sternberg and Cynthia Berg offer a comprehensive overview of current theoretical and empirical work from six different perspectives to intellectual development: psychometric, Piagetian, neo-Piagetian, information-processing, learning, and contextual. Although these different perspectives to intellectual development have often been at odds, the book shows that taken together, each perspective adds important components to the puzzle of intellectual development. Common themes arise within and across particular perspectives, which suggest a more unified view of intellectual development may emerge as boundary lines between perspectives and developmental periods diminish.