Pubescent boys and men are normally the only people who grow beards, but women suffering from hirsutism can develop a beard. When differentiating between upper and lower facial hair, a beard specifically includes the moustache, which refers to hair above and around the upper lip. Over the course of history, men with facial hair have been ascribed various attributes such as wisdom, sexual virility, masculinity, or a higher status; however, beards may also be perceived to be associated with a lack of general cleanliness and a loss of refinement, particularly in modern times.
Biologists characterize beards as secondary sexual characteristics because they are unique to one gender, yet do not play a direct role in reproduction. Charles Darwin first noted a possible evolutionary explanation of beards in his work The Descent of Man, which hypothesized that the process of sexual selection may have led to beards. Modern biologists have reaffirmed the role of sexual selection in the evolution of beards, concluding that there is evidence that a preponderance of females finds mates with beards more attractive than mates without beards.