In 1978, Hulse, Fowler, and Honig published Cognitive Processes in Animal Behavior, an edited volume that was a landmark in the scientific study of animal intelligence. It liberated interest in complex learning and cognition from the grasp of the rigid theoretical structures of behaviorism that had prevailed during the previous four decades, and as a result, the field of comparative cognition was born. At long last, the study of the cognitive capacities of animals other than humans emerged as a worthwhile scientific enterprise. No less rigorous than purely behavioristic...