["Journal of the Experimental Analysis of Behavior, Volume 126, Issue 1, July 2026. ", "\nAbstract\nDr. Warren Bickel tirelessly investigated delay discounting (DD), a behavioral economic index of impulsive decision making, as a determinant of numerous health outcomes. Among the factors that contribute to a person's level of DD, a burgeoning body of research has illuminated its genetic foundations and the extent to which it may be a mechanistically informative phenotype for genetic contributions to addiction, obesity, attention‐deficit/hyperactivity disorder, and a wide array of other health behaviors. In this review, we provide a concise history of quantification of DD as a human decision‐making phenotype, tracing its origins from economics and operant learning theory, and critically synthesize the existing evidence on its genetic architecture. Finally, despite innate genetic contributions, we also discuss evidence that DD is a modifiable health behavior, with high potential in precision medicine.\n"]