Men grow facial hair because of the stimulatory effects of male hormones like testosterone. Professor Paul Sherman of Cornell University believes that it is likely that a beard’s colour and texture played a role in ‘sexual selection’, meaning beards were useful for attracting mates or intimidating rivals. A beard could cushion a man’s face against blows in a fight and hide scars from previous fights.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.
