Women want something different, which means that your beard is only attractive if you are surrounded by shaven-faced guys, according to a new study from the University of New South Wales.

The study used an audience, consisting of mostly women, to view a series of 36 images of Men’s faces. The first 24 images were used to condition the audience. They would either all be images of bearded men, or all images of clean shaven men.

The last twelve images would either be a continuation of the trend (if the first 24 bearded, last 12 also bearded), or show the opposite of the trend (if the first 24 clean shaven, last 12 bearded).

The study found that rarity determined attractiveness.

The audience found beards attractive, if they hadn’t already seen a lot of them in the previous images. Similarly, the audience found clean shaven men attractive if they were underrepresented in the 36 photos.

Scientists refer to the phenomenon as “negative frequency-dependent sexual selection”. It may be an important factor in how we select our partners, with our brains favouring ‘rarer’ genes

“It appears that beards gain an advantage when rare, but when they are in fashion and common, they are declared trendy and that attractiveness is over,” said Researcher Robert Brooks to the Guardian in Australia.

“The bigger the trend gets, the weaker the preference for beards and the tide will go out again.”

He also believes that before the internet a cycle like the beard fad may have lasted for up to 30 years. But because of our interconnected world, beards may soon become so last season.