In the interwar period between 1918 and 1945, before the programmable computer and information theory were mobilized by biologists and economists as heuristics and instruments, the study of "man the animal" as a biological and social being was a managerial and bureaucratic pursuit. This pursuit was informed by changes in organization, the work process, and other institutions then taking place across wide swaths of American society. Coming as it did from such diverse sources, the field of human biology was always a loosely organized project, whose elements were in dynamic tension with each other. Human biology's research and popularizations would also necessarily be in tension with earlier eugenic arguments about heredity, even as they shifted the focus of concern onto the fields of human population growth, human variability, and social order. Two of the biggest recipients of human biology funding in the 1920s were the research groups led by Raymond Pearl at Johns Hopkins University and Lawrence Henderson at Harvard, particularly its business school. Henderson and Pearl were not only interested in solving social problems but also in establishing themselves in their fields. This consideration influenced their choice of audiences away from reform-oriented intellectuals and towards those they most directly needed to convince of their project's efficacy: university administrators, government officials, and business managers. For Pearl the problem of population growth and the differential rate of reproduction between native whites and immigrants would resolve itself through the natural action of the population's self-regulating capacities. Henderson on the other hand, and his allies at Harvard Business School Elton Mayo and Wallace Donham, saw an organizational and social world thrown badly out of equilibrium by the rapid changes of the early 20th century. They prescribed an elite cadre of manager-administrators to play a leading role in the key institutions of American life in order to reestablish equilibrium through their knowledge of "man the animal." What united Pearl and Henderson politically was their elitist conceptions of citizenship and science, and their animosity for progressive social reform, "uplift" and the New Deal.