Scientists think they may have solved one of the great mysteries of the age. Why are so many of today's men growing beards?
The answer, according to The University of Western Australia researchers, is because men are feeling under pressure from other men and are attempting to look aggressive by being more flamboyant with their whiskers.
Published in the journal Evolution and Human Behaviour, Dr Cyril Grueter and colleagues were investigating the idea that in big societies, male primates have developed increasingly ostentatious "badges" which may enhance male sexual attractiveness to females and give them the edge over other males.
These include cheek flanges in orang-utans, elongated noses on proboscis monkeys, upper-lip warts in golden snub-nosed monkeys - and beards on humans.
The team investigated 154 species of primates, and found more conspicuous badges in males of species where social and physical conflict were common and individual recognition was limited.
i.e. The busier and more crowded with males a society becomes, the more competition there is and the more flamboyant the badges are.
The modern male not only has to vie with hundreds of fellow males in the real world but has to stand out from potentially thousands of rivals online, so clean-shaven may well be turning off women who are drawn to seemingly powerful men.
"When you live in a small group where everyone knows everyone because of repeated interactions, there is no need to signal quality and competitiveness via ornaments," he said.
"In large groups where individuals are surrounded by strangers, we need a quick reliable tool to evaluate someone’s strength and quality, and that’s where these elaborate ornaments come in.
"In the case of humans, this may also include phenotypic extensions such as body decoration, jewellery and prestige items."
But the phenomenon is not necessarily a modern one. In their paper, the authors also argue that the popularity of moustaches and beards among British men from 1842 -1971 rose when there were fewer females in the marriage pool and beards were judged to be more attractive.
During the 19th century, the attitude to facial hair changed as a result of the wars in India and Asia. Many Middle Eastern and Indian cultures associated wisdom and power with facial hair so as a result, beards, moustaches and side whiskers in particular, became more common on British soldiers stationed in the east.
