In a study, which polled more than 8,500 women, men with stubble were seen as the most attractive overall.
They were also seen to be more attractive for short-term relationships, while men with full beards were seen as desirable for long-term relationships.
The study’s authors said beards acted as a signal of a man’s age and social dominance, which could explain why women prefer that type of facial hair in a long-term relationship.
For the study, which was published in the Journal of Evolutionary Biology, women were asked to rate photos of men in terms of their general attractiveness, as well as whether they’d like to have a short-term or long-term relationship with them.
Each woman was shown four photos of 16 different men, which had been digitally manipulated to show the various stages of beard growth: clean-shaven, light stubble, heavy stubble and full beard.
Researchers found that stubble was considered the most attractive type of facial hair, and men with beards were considered more attractive than clean shaven men.
Women involved in the study were also asked what type of facial shape they found most desirable, after researchers digitally manipulated the photos of each man to appear less or more masculine.
They discovered that men with feminine faces and zero facial hair were deemed to be less attractive than unmanipulated faces that were clean-shaven.
‘Extremely masculine’ and ‘extremely feminine’ faces were also deemed less attractive.
Interestingly, longer facial hair - such as full beards - were seen as attractive for women looking for long-term relationships.
The researchers concluded: “Our findings suggest that beardedness may be attractive when judging long-term relationships as a signal of intra-sexual formidability and the potential to provide direct benefits to females.”
In other words, said researcher Dr Danielle Sulikowski, beards tend to be associated with qualities such as strength, stability and power.
She told News.com.au: “In other studies, we know that men view other men who have beards as quite dominant, more mature and high ranking, so we know that a full beard can become a sort of status symbol.”