Somatotyping is a now-discredited theory of human body-typing, reminiscent of phrenology in its desire to judge people by the shapes of (parts of) their bodies.
A man named William H. Sheldon made this his life work, photographing tens of thousands of students at Yale University, Mount Holyoke, Vassar College, Smith College, Princeton University, and other schools from the 1930s to the 1960s.
He divided these into endomorphs (fat), mesomorphs (fit) and ectomorphs (skinny). This became a scandal in the mid-1990s, when it was revealed that the photographs still existed of many of America's business leaders and political leaders, naked.
Sheldon was by no means alone. Harvard University, for example, took “posture photos” from the 1880s through the 1940s.