The problem and the solution. Human capital theory is a well-accepted foundation of human resources development (HRD) research and practices. Screening theory is equally foundational to HRD. This article presents and compares the two seemingly contrasting theories in economics. The origins, evolution, and current states of research on both theories are explored. The focus of the article is to identify their foundational role in, and implications for, HRD research and practice.The article shows that the two theories are complementary and have important implications for HRD theory building, research, and practices.