The first three waves of research on resilience in development, largely behavioral in focus, contributed a compelling set of concepts and methods, a surprisingly consistent body of findings, provocative issues and controversies, and clues to promising areas for the next wave of resilience research linking biology and neuroscience to behavioral adaptation in development. Behavioral investigators honed the definitions and assessments of risk, adversity, competence, developmental tasks, protective factors, and other key aspects of resilience, as they sought to understand how some children overcome adversity to do well in life. Their findings implicate fundamental adaptive systems, which in turn suggest hot spots for the rising fourth wave of integrative research on resilience in children, focused on processes studied at multiple levels of analysis and across species.