Once the sole province of grandfathers, lumberjacks and fugitives from justice, beards have established themselves firmly in mainstream fashion.
Now University of WA researchers have drawn a link between the beard's return to popularity and the display habits of primates.
UWA researchers, led by School of Anatomy associate professor Cyril Grueter, found male primates that lived in big groups had more "conspicuous badges" than those in smaller groups.
Such identifiers allowed them to "signal their identity, rank, dominance and attractiveness".
"This is where these ornaments come in handy," Dr Grueter said. "So these males, they have these flamboyant ornaments and they use them to signal their quality and their status to other individuals in the group.
"Ornaments include, for example, the long fat noses of the proboscis monkey or the reddened chest of the gelada (baboon) . . . and possibly also beards in humans."
Dr Grueter said men with beards were perceived as more masculine and dominant. "So it is possible that male facial hair is the result of inter-male competition," he said.
Theo Zeppos, who owns The Barber Shop in Leederville, said he grew a full beard six months ago as a way to test beard products.
"Now I like it, my wife likes it . . . Mum hates it," he said.