It’s amazing how opinionated people can get about hair—whether it’s about how it should be groomed or whether it should even exist in certain places. Facial hair is no exception—some love it, some don’t mind it, and others prefer it gone. In fact, the obsession with facial hair can sometimes reach extraordinary heights. Remember the 2012 mustache craze? People were so caught up in it that they even got mustache tattoos on their fingers. For those who are into beards, there’s even a dating site called Bristlr.

The fascination with facial hair isn’t new, but why can men grow beards while women generally can’t? It all comes down to hormones. Men’s facial hair follicles are influenced by dihydrotestosterone (DHT), a potent derivative of testosterone. Although DHT has a reputation for being less prominent than testosterone, it plays a crucial role in stimulating beard growth.

Women have the same number of hair follicles on their faces, but theirs are less responsive to DHT, and they also have lower levels of testosterone. That’s why beards are a predominantly male trait.

The biological role of a beard remains a bit of a mystery to scientists. Unlike eyebrows, which keep sweat out of your eyes, and eyelashes, which shield against dust and debris, beards don’t have a clear practical function in everyday life. Still, researchers have proposed some intriguing theories to explain why men grow them.

Dr. David Carrier, a comparative biomechanist and Professor of Biology at the University of Utah, suggests that beards might have evolved as a way to protect men’s vulnerable bones during physical confrontations.

“If the desire is to actually kill another individual, we tend to show up with weapons,” he reasoned. “If the desire is just to control or manipulate another individual, then you’re going to get hand-to-hand fighting; in that physical combat situation, humans tend to use their fist, and the primary target when we strike is the face.”

A punch to the face is most likely to damage the jaw—epidemiological studies show that the lower jaw is the most frequently broken bone from such impacts. “We’re thinking that it may not be a coincidence that it is primarily the jaw that is covered by the beard,” Dr. Carrier said.

In the study conducted by Dr. Carrier and his team, they set out to find out if facial hair could protect against punch damage. An undergraduate student built models with either shaved or unshaven skin on top of fiber composite. Using a drop weight impact tester, they measured how much force was absorbed when weights were dropped on the models.

“The results really surprised me,” Dr. Carrier said. “The forces were 16 percent greater when the fur wasn’t there, and about 40 percent more energy was absorbed when the fur was there.”

Other researchers think beards might serve as a way to send certain signals to both men and women. As evolutionary psychologist Geoffrey Miller puts it: “The two main explanations for male facial hair are intersexual attraction (attracting females) and intrasexual competition (intimidating rival males).” In simpler terms, facial hair can suggest virility and sexual maturity to potential partners, as beards tend to appear after puberty, while to rivals, it may signal strength and masculinity.

However, whether a beard actually makes a man more attractive is still up for debate. Some studies find that women prefer men with stubble over full-grown beards or clean-shaven looks. Meanwhile, other research shows that attractiveness ratings don’t always align with beard growth—meaning clean-shaven faces can be just as appealing as bearded ones.

Interestingly, another study found that women tend to find a man more attractive if he sports a beard when most other men around are clean-shaven. But if beards become more common, shaving might give a man an edge instead. This is known as negative frequency dependence—an evolutionary principle where having a rare trait is considered more appealing and advantageous for survival.

Cultural preferences also play a big role in how beards are perceived. In the UK, more than 50% of men have some form of facial hair, while in South Korea, you’ll probably see fewer men with beards, and many even go so far as to have it permanently removed. In East Asia, where facial hair tends to be sparser, growing a full beard can be challenging. Even so, in South Korea, there’s a belief that those who don’t shave are considered less attractive because it suggests they don’t take as much care of their appearance.

Although people don’t always agree on the appeal of beards, it’s pretty clear that facial hair changes how you’re seen by others. Men with beards are often thought to be older and are frequently associated with higher social status. They may also come across as more aggressive, and increased beard growth is linked to a stronger perception of masculinity.

So, if you’re thinking about growing a beard but are worried about how others might see you, don’t let that hold you back. Even scientists can’t quite agree if it makes someone more attractive. What really matters is how it makes you feel. Just remember to take some before-and-after photos of your beard journey and share them online—you might even end up in one of our compilations. Good luck!