C. G. Jung and W. H. Sheldon
If you are interested in human typology, see here. I first read about Sheldon's somatotypes in George Sheehan's On Running, his first and best book. That was before Sheehan became famous and started writing books with such portentous titles as Running and Being. Try this at your next road race. Ask the younger runners if they know who George Sheehan was. George who??