Comparative Psychology (second edition) is a core textbook for senior undergraduate and graduate courses in Comparative Psychology, Animal Behavior, and Evolutionary Psychology. Its main goal is to introduce the student to evolutionary and developmental approaches to the study of animal behavior. The structure of the book reflects the principal areas of importance to psychology students studying animal behavior: evolution, physiological issues, learning and cognition, development, and social evolution. Throughout, this text includes many examples drawn from the study of human behavior, highlighting general and basic principles that apply broadly to the animal kingdom.