1844–1924 · American psychologist · founder of the American Psychological Association
Granville Stanley Hall was a pioneering American psychologist and educator, the first president of the American Psychological Association and of Clark University. His two-volume Adolescence (1904) popularized the study of youth and contained the earliest English form of the play-and-aging idea — “men grow old because they stop playing” — which he adapted from Karl Groos. The polished modern proverb is a later, anonymous reworking of that thought, and has nothing to do with Benjamin Franklin.