Just last year, a psychological study found that women considered men with heavy stubble to be more attractive than clean-shaven or full-bearded men. But when the women were asked to rate a man's face based on their impression of his parenting ability, the full beard came out on top.

The study involved showing volunteer women pictures of men at different stages of beard growth, which means the results weren't skewed by one man being more attractive than another, regardless of facial hair.

But of course, says the latest episode of RiAus, that's just one study, and the reality of facial hair and attractiveness is not that clear cut. While studies have shown that stubble is most attractive to surveyed women, the heavier it becomes, the less consensus there is about its attractiveness. In fact, the bigger the beard, the more aggressive the man is perceived to be. And throughout periods in history when beards have enjoyed the status of being fashionable, they're actually seen as less attractive than clean-shaven faces, because they've become so common.

Similarly, the closer to clean-shaven the stubble gets, the less attractive it's perceived to be. And in times where clean-shavenness is most popular among the men, it's seen as less attractive by women, due to how common it is.

So it's not just about how different types of facial hair look, it's also about what's fashionable, and how many people are sporting each type of look.

Want to know why stubble is the most attractive form of facial hair? Watch the latest episode of RiAus's A Week in Science above to find out. And congratulations to RiAus for launching Australia's first dedicated science channel!

The guys at AsapSCIENCE have also weighed in on the beard vs clean-shaven debate. Check it out here.

Source: RiAus