Pavlov claimed that his experiments with dogs would transform the study of psychology and the treatment of mental illness. His work inspired researchers to study how animals learn to traverse mazes, avoid shocks, or press levers to obtain food, and also to compare the learning and cognitive abilities of different species, ranging from apes and dolphins to rats and pigeons. This book describes five decades of research into animal learning and comparative psychology, examining Pavlov's influence on this research and discoveries made by scientists who accepted many of his claims, while others looked for evidence to reject them. Drawing together diverse strands of research and providing historical and biographical information to bring the details to life, this is an ideal resource for graduate students and researchers in behavioural neuroscience, as well as for anyone in adjacent fields with an interest in learning theory.