In this new book, Robert W. Proctor curates a collection of celebrated and seminal articles from the past 125 years of the American Journal of Psychology . The debut volume in the University of Illinois Press ™s Common Threads series, Higher Mental Processes reprints a suite of ten articles on processes of higher-order thinking. Proctor, current editor of the AJP , begins the volume with a special introduction that provides historical and scientific context for the contributions. Contributors: P. Baratta, M. H. Birnbaum, M. E. Bulbrook, L. S. Buyer, R. A. Carlson, S. N. F. Chant, A. A. Cleveland, T. D. Cutsforth, R. L. Dominowski, E. Galanter, P. N. Johnson-Laird, M. G. Preston, Robert W. Proctor, and J. Tagart.