Early warning systems (EWSs) have traditionally focused on collecting and analyzing hazard data to produce warning messages that help inform stakeholders of impending disasters and when, where, and how to initiate response activities. Social constructivist understandings of risk have led to more people-centered approaches to EWS design and development. The resulting systems, though better informed, have consistently struggled to produce the preparation and early actions of exposed and vulnerable populations. This paper builds on decades of psychology and social and behavioral change theory and practice to propose a social and behaviorally informed approach to EWS design, development, and implementation. The approach focuses on identifying proper early actions and the determinants of those behaviors in order to improve the likelihood that affected populations heed early warnings and take proper action to protect themselves and the resources they may require for recovery.