Behavioral economics has a lot to contribute to effective policies and other applications. As evidence in this area accumulates, the field will increasingly provide direct insights for applications that maximize policy outcomes, particularly to those with a direct relationship to human choices and behaviors. To realize this potential, it is necessary to understand the psychological theory and the mechanisms currently used to study behavior, as well as the historic development of the field. While much was traditionally understood through the lens of classical economics, recent trends have expanded to include findings from psychology, neuroscience, and sociology, to name a few, leading to the areas of scientific study commonly referred to as behavioral science and behavioral economics. Findings from these domains are typically known as behavioral insights. They are often characterized by the use of behavioral constructs to explain patterns in the behavior of groups or single individuals. Many influential individuals from these domains have propelled our knowledge of the field, exploring the idiosyncratic ways in which behavior and decision-making affect our daily lives. This chapter provides a brief history of how this field came to be so academically influential while outlining the work of leading figures and concepts necessary to understand, study, and implement these behavioral insights.