Underappreciated by historians of the human sciences, educational psychologist Mark A. May played a key role in managing and formulating the policy of the Institute of Human Relations at Yale University, initially as the institute’s executive secretary, then as its director, from 1930 to 1960. Moreover, during the 1920s, the 1930s and after, he participated in a number of conferences, seminars, committees and other projects sponsored by the Social Science Research Council and Rockefeller philanthropic organizations. Focusing on May’s efforts during (...) the interwar period, this article will examine how May worked to advance an integrated program in the psychological and social sciences affiliated with the field of personality and culture. For May, a human engineering agenda geared toward the socialization and education of the individual was intimately connected to his vision of interdisciplinary social science. (shrink)