The Ivy League nude posture photos were taken in the 1940s through the 1970s of all incoming freshmen at Harvard, Yale, Princeton, the University of Pennsylvania (which are members of the Ivy League) and Seven Sisters colleges (as well as Swarthmore), ostensibly to gauge the rate and severity of rickets, scoliosis, and lordosis in the population. The photos are simple black-and-white images of each individual standing upright from front, back and side perspectives. Harvard previously had its own such program from the 1880s to the 1940s. The larger project was run by William Herbert Sheldon and Earnest Albert Hooton, who may have been using the data to support their theory on body types and social hierarchy.