A fresh new look at the science of human and nonhuman behavior, focusing on how evolution shapes choices and actions of all kinds Although traditional, reinforcement-based approaches to behavior have proven to be ineffective, the field of applied behavior analysis is alive and well. Introduction to Behavior: An Evolutionary Perspective introduces readers to contemporary perspectives on why people and other organisms do what they do. Examining the concepts of behavior and organism from within an evolutionary framework--including how natural selection influences species-wide tendencies--this book sets a foundation for observing, measuring, and understanding behavior. Founded on up-to-date research and written by one of the leading scholars in the field, this book explores why and when behaviors change (or stay the same), how environmental inputs interact with evolution to produce behavioral outcomes, and how evolutionary theory can be mobilized to explain verbal, social, and cultural behavior phenomena. Filling an important need for a new conceptual framework in basic and applied behavior analysis, Introduction to Behavior trains undergraduates, graduate students, and professionals to study and theorize about behavior through the powerful lens of evolution.