The Department of the Army, through the U.S. Army Research Institute for the Behavioral and Social Sciences (ARI), is soliciting proposals for fundamental research in behavioral and social sciences for fiscal year 2026. This Broad Agency Announcement aims to address critical scientific challenges related to Soldier readiness, focusing on foundational research that enhances operational capabilities, personnel development, and organizational effectiveness. The research will encompass four key domains: Measurement of Individuals and Collectives, Teams and Small Groups, Organizations and Systems, and Formal and Informal Learning and Development, with an emphasis on advancing psychological measurement methods and optimizing team dynamics. Interested applicants, primarily from higher education institutions, non-profits, or commercial entities, should submit white papers followed by full proposals, adhering to the outlined eligibility criteria and evaluation guidelines. For further inquiries, contact Kimberly Wingert at kimberly.m.wingert.civ@army.mil or Wilveria Sanders at wilveria.a.sanders.civ@army.mil.