Since the late Middle Ages periods in which it was fashionable for men to be clean-shaven have alternated in Europe with periods in which it was fashionable for men to wear beards. In some periods clean-shavenness went together with long hair, at others beards went together with short hair, and sometimes it was the other way round: no beards, and short back and sides, or beards and long hanging locks. One inevitably wonders why and how such changes in fashion occur, and, more specifically, whether such permutations in hairstyle mean anything in symbolic or psychological terms: whether they have anything to do with Zeitgeist.

All human males have hair that grows steadily, and, after puberty, beards that have a greater or lesser tendency to sprout. The statement of Sir Edward...