This book aims to develop, in every reader, the ability to scientifically interpret why they feel, think, perceive, and act in the way that characterizes them, and, if they wish, to intervene, to regulate the conditions in order to change these psychological phenomena. Instead of attributing behavior to hypothetical, mysterious activities of the mind, the book describes how each psychological phenomenon can be understood through the long-term interaction of the biological organism with the natural events of its life (smiles, slaps, tastes, sights, sounds, etc.), the products of its own behavior, which provoke stimulation and emotions, and which change the likelihood of acting again in the way that caused it.

For psychologists, educators, health professionals, and other practitioners responsible for regulating conditions aimed at the development or improvement of others' behavior, the book serves as a comprehensive introduction to an interpretation of the origins of behavior based on experimental analysis, with direct and effective applications in their field. However, it is also a book that broadly interests every reader because it offers a truly different, interesting, and practically beneficial understanding of themselves, as it introduces them to a psychology consistent with the natural and biological sciences, which, like them, enriches the human's connection with the natural world.