Men grow beards, social psychologist Robert Brooks explains, as a form of plumage. The display of facial hair advertises a man’s virility to prospective mates and rivals, and helps him stand out from the crowd. It’s an effective strategy, until lots of other men conform to the nonconformity. “Beards gain an advantage when rare,” Brooks says, “but when they are in fashion and common, they are declared trendy and that attractiveness is over.” Indeed, a 2013 Australian study found that when a majority of men are bearded, women begin to find shiny, clean-shaven faces more attractive. What does this tell us? Something yet undiscovered by the young, but obvious to those who’ve been through a few fashion cycles: What is cool today will look comically affected tomorrow. The image you carefully cultivate at one point in your life will make you cringe in embarrassment years later. If you don’t believe me, let me show you my photos from age 28, when I was rocking a (unironic) mustache. I thought it looked rather rakish at the time.