Medical science, one trim at a time
The Economist on pogonophobia and pogonophilia.
Many also believed that not shaving offered health benefits. In 1854, more than 400 members of the Dublin police force petitioned to be allowed to join the beard movement on the ground that “almost all, if not all, diseases of the respiratory organs are in great part, if not altogether, caused by the practice which obtains of shaving off the beard.” Beards were even thought to bring productivity gains. An article in the British Medical Journal in 1861 calculated that America lost 36m working days each year to shaving.
The beard craze petered out in the 1890s as fashions shifted, better razors became available and doctors took to warning against facial hair (a damp beard was thought to spread germs). Beards became the preserve of older men as the young rejected the fashions of their fathers. The army was slower to adapt. The requirement for moustaches lasted until 1916; some regiments maintained a stockpile of artificial ones for those unable to grow their own.
Note the tendency to take tenuous and marginal observations and multiple by a big number to make them seem important. Epidemiology 101, sadly, (but beloved by all grant writers).