Traditional views of abilities have viewed them as internal properties of the organism. The views presented in this book, in contrast, view abilities as inhering in the interaction between minds and the contexts in which they are found. Some of the greatest psychologists of all time, such as Piaget and Vygotsky, have recognised the importance of person-context interaction to the development of intelligence, and even fervent hereditarians have recognised the extent to which when genotypes are expressed phenotypically, there is a reaction range that can limit or enhance the extent to which the genotype is expressed in the environment. The book is divided into three main parts. Part I, focusing on academic tasks, Part II, focusing on everyday tasks, and Part III, containing general perspectives.