This book investigates the biological and environmental determinants of human happiness, specifically questioning how early childhood experiences shape an individual's lifelong capacity for emotional well-being. Paul Martin, a behavioral biologist, synthesizes research from developmental psychology, evolutionary biology, and neuroscience to move the study of happiness away from philosophical abstraction and toward empirical analysis. He argues that happiness is not merely a byproduct of success but a measurable, developmental trait influenced by parental guidance and educational environments.

The text provides a rigorous, science-based approach to a subject often dominated by subjective self-help literature. Its focus on developmental biology offers a structured, analytical perspective for readers seeking to understand the mechanisms behind emotional health.