Two dozen brief essays by the foremost experts in the field are presented in this volume. Each researcher comments on the nature of intelligence, its measurement, and the future of research in the field, bringing his or her own perspective to bear on the issues. Truly diverse viewpoints are represented: cognitive psychology, developmental psychology, psychometrics, artifical intelligence, cross-cultural psychology, educational psychology, and differential psychology. An introduction that sets an historical and philosophical context, and two essays that interrelate the contributions, complete the volume.