When we think of Charles Darwin, what comes to mind? Natural selection. The Galapagos Islands. And if we are picturing him, he has a rather impressive beard.

It turns out that among the many puzzles of biology that Darwin tried to solve was why human males have the propensity to grow beards. In “The Descent of Man” (1871), Darwin speculated that beards may not directly enhance survival in contrast to claims from a recent study suggesting that facial hair’s function may be to absorb some of the impact of getting punched (Beseris et al., 2020). Instead, Darwin argued that beards might be considered an “ornament,” much like a male peacock’s bright tale feathers.

In this line of thinking, facial hair made our male ancestors more attractive to the opposite sex. Thus, genes that made men more hirsute were more likely to be passed on. A process known as sexual selection. Sometimes, but not always, sexual selection works to amplify characteristics that enhance fitness in some other way, i.e., upping the odds of survival or success in competition. Or that signal other underlying traits, like good health or intelligence, that have important implications for the fitness of any potential offspring.

But does facial hair actually make men more appealing? And what other traits might a beard provide clues to? If sexual selection did indeed favor more facial hair, then we might expect women to find bearded men more attractive. The first empirical tests of this prediction didn’t come until the late 1960s, nearly a century after Darwin put it forth. Results were mixed, with some studies finding that men with beards were........

© Psychology Today