I once walked down the long hallway of a medical school that featured class pictures of every year back into the 1800s. The black and white photos made it visu

I once walked down the long hallway of a medical school that featured class pictures of every year back into the 1800s. The black and white photos made it visually apparent which years had more facial hair (until more recently when women started being admitted). I have always wished I'd taken the time to count the data and look at the pattern... but it turns out someone has already done this research.