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Did men's beards evolve to absorb a punch to the jaw?

A man with a beard takes a punch to the jaw.
In a brawl, a beard may soften a blow.
(Image: © Shutterstock)

Full, luxurious beards are a sight to behold, and they may also serve a practical purpose — softening the impact of a punch to the jaw.

Throughout history, flowing beards have been celebrated by cultures around the world as an emblem of social dominance and virility, much like the flowing mane of a dominant male lion.

However, the thick hair of a lion's mane also protects a big cat's throat against a rival's lethal claws and teeth, scientists have said. And a dense beard may lend similar protection against deadly attacks by cushioning and absorbing forces directed at the jaw, the facial bone that breaks the most often during combat, researchers recently suggested. 

Related: Fight, fight, fight: The history of human aggression

Charles Darwin, celebrated naturalist and father of evolutionary theory (who was also the owner of a magnificent beard) had something to say about facial hair. Though Darwin saw the lion's mane as a source of physical protection, he viewed the human beard as merely an "ornament" for attracting female attention, scientists reported in a new study, published online April 15 in the journal Integrative Organismal Biology

The study authors proposed otherwise. They argued that hairs in a beard would collectively diffuse the force of a blow and so may have evolved in response to the need to win male-male battles. A growing body of evidence hints that human skeletons and muscles evolved to support specializations linked to male fighting; other researchers have previously suggested that male facial shapes evolved to protect the face from damage during combat, according to the new study. It could therefore be possible that beards evolved for the same reason, the authors said.

To test that idea, the scientists built models that approximated the structure of bone in a human skull. They cut the bony material into bricks and wrapped them in sheepskin fleece, "because it was not practical to obtain fully bearded skin samples from human cadavers," the researchers wrote. While sheep's fleece wasn't a perfect analogue for beard hair, "the volume of follicles in our fleece samples did approximate the volume of full beards, which is unlikely to be true for the pelts of most other species," they said. 

Three types of sheepskin coverings were used for the experiments. Furred samples, where the sheep's wool was left at its full length, tested the effectiveness of a full beard at cushioning an impact. Sheared samples told the scientists if the roots of hair follicles provided any protection, while plucked samples represented a beardless jaw.

The researchers then conducted drop-weight tests, placing the sheepskin-wrapped "bone" bundles on an anvil and releasing a blunt rod from overhead.

The experimental setup, using an Instron Dynatup 8250 drop weight impact tester.

The experimental setup, using an Instron Dynatup 8250 drop weight impact tester.  (Image credit: E. A. Beseris, S. E. Naleway and D. R. Carrier/Integrative Organismal Biology)

The "furred" bundles fared best against the heavy weight, absorbing nearly 30% more energy than the bundles that were sheared or plucked. Under a  machine setting for an impact that damaged all of the plucked samples and 95% of the sheared samples, only 45% of the furred samples cracked or shattered. Furred samples also took longer after an impact to reach their breaking point than did the other samples.

"The results of this study indicate that hair is indeed capable of significantly reducing the force of impact from a blunt strike and absorbing energy, thereby reducing the incidence of failure," the scientists said. 

"If the same is true for human facial hair, then having a full beard may help protect vulnerable regions of the facial skeleton from damaging strikes, such as the jaw. Presumably, full beards also reduce injury, laceration and contusion, to the skin and muscle of the face." 

How exactly does that work? Individual hair fibers likely absorbed energy from the punch and distributed incoming force over a larger area, the researchers said. However, more experiments would be required to precisely explain the mechanisms through which this protection happens. Human facial hair can also vary widely in coarseness, thickness, curl and density; and different beards may vary in their effectiveness at warding off damage from impacts, according to the study.

Originally published on Live Science.

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  • jermcat
    So why didn't males just hold on to thick Neanderthal jaws?
    Reply
  • Kchoonit1949
    jermcat said:
    So why didn't males just hold on to thick Neanderthal jaws?
    the more important question, why do men shave???
    Reply
  • Marsha;;
    Men shave due to Trench Warfare in World War One.
    Reply
  • christophermark
    Alexander the Great is said to have initiated shaved beards to prevent enemy combatants from grabbing hold of the beard with one hand and clobbering with some weapon in the other. Hand to hand combat (especially jaw punching) would be, practically speaking, a third-rate strategy. Weapons aimed to expedite the opponent with a single action requires less energy overall. Since weapons in prehistoric times brought down game animals (according to cave paintings), there is little reason to believe they weren't used in tribal warfare. Some chimps have been observed using clubs in warfare, and dance what appeared to be war dances using clubs. The working hypothesis that beards deflect blows, and therefore had evolutionary value for that reason is open to question, to say the least. A trained warrior would, in any case, go for the nose or the forehead rather than the jaw, using the heel of his hand if no weapon were available.
    Reply
  • jmnp08
    I am going to say no. It's silly really. The amount of energy absorption from this would be minimal. It could, potentially decrease the chance of sustaining a laceration from a blow. That being said it would be very much used against you. Long hair on any body area is a grip.
    Reply
  • Potgoblin
    christophermark said:
    Alexander the Great is said to have initiated shaved beards to prevent enemy combatants from grabbing hold of the beard with one hand and clobbering with some weapon in the other. Hand to hand combat (especially jaw punching) would be, practically speaking, a third-rate strategy. Weapons aimed to expedite the opponent with a single action requires less energy overall. Since weapons in prehistoric times brought down game animals (according to cave paintings), there is little reason to believe they weren't used in tribal warfare. Some chimps have been observed using clubs in warfare, and dance what appeared to be war dances using clubs. The working hypothesis that beards deflect blows, and therefore had evolutionary value for that reason is open to question, to say the least. A trained warrior would, in any case, go for the nose or the forehead rather than the jaw, using the heel of his hand if no weapon were available.

    Actually that's too simplistic. Alexander the Great prefered clean shaven, however, short beards are sufficient--you can't grab short beards, yet he preferred clean shaven and not scruffle (which you can't grab). The historical reason why Alexander the Great preferred clean shaven is, through hygiene, to distinguish his army from those dirty uncivilized barbarians. Same reason why the US military prefers clean shaven, it's not because beards are grabbable--but because soldiers look cleaner and more disciplined.

    More importantly though, grabbing a beard while you opponent has a weapon is not a good idea. You lose one arm since it is tied up, and your opponent has two arms to attack with. I dare you to grab your opponents beard while they are swinging their sword and shield at you. One little cut to the arm and you'll bleed to death. Grappling is a bad idea in such combat situations. In fact, if I'm in a fight with knives, I'd prefer my opponent grab my beard/shirt, that (1) puts them in range and (2) gives them one less arm to defend with while I have two. That would be way better than if they keep a distance from me, strike and then retreat and we wail our knives around--I'd rather be grabbed and be in range.

    Now you said something about going for the nose or forehead rather than the Jaw if the opponent has a beard--while that is true, consider that without a beard the opponent can go for the nose, forehead AND Jaw. So having a beard is better than not considering your scenario. Also note that attacking the nose/forehead is different from attacking the soft tissue of the Jaw/Neck.

    Large beards may also be helpful to hide the location of the Jaw so it is harder to target. Also helps protect against neck lacerations from sharp weapon slices. Also helps make you look like a formidable opponent--fear is a major factor: if your opponent is scared and threatened by you and you see them as weaker, that is and advantage and they might get submissive and lose the fight. If you feel that you are bigger and stronger than your opponent, and the opponent sees that they are smaller and less formidable, that is an advantage for you. Confidence and morale is very important in a fight. We see this a lot in boxing/MMA, one fighter is confidently just throwing fists and the other opponent being less confident doesn't throw fists as well gets on the defensive and gets knocked out.

    Other notes: When vision is hampered by dizziness or blood, and/or if a fighter is merely surviving and striking out on instincts, a big beard could have the effect of throwing off someone's aim just enough to potentially help the bearded fighter stave off damage from strikes to the chin area. The beard kind of acts as a form of camouflage, it blurs the contour of the wearer's facial structure--especially like a large bushy one. Beard hairs tend to be coarser than head hairs.

    This article may be on to something on top of that. The question is: will the reduction of force from a heavy punch by a beard be significant enough, or is it not significant? Sure the beard reduces the force, but is that reduction enough to not get knocked out? Maybe it can be with weaker punches and that is significant enough to yield better outcomes (since perhaps being without a beard and being attacked by those same weaker punches would do more harm than if you have a beard), but I'm not so sure.

    One more thing to mention: there is no reason to think that stone age humans couldn't/didn't cut their hair. Even in extant hunter gatherers, they all do "hair stuff" and cut their hair. Even using stone tools, or clams to trim their hair. These humans are hunting animals and likely know how to cut meat and cut animal skin--they can also cut their own hair--especially if it gets in the way. So now, if you have a beard that you can trim: you can gain the advantages of camouflaging your chin area and intimidating your opponent reducing their confidence/morale in a fight (which is an advantage for you in a fight) while keeping your beard short enough such that grabbing it is difficult and thus not as much of a disadvantage. Beards thus can confer significant advantages compared to not having one.
    Reply
  • Potgoblin
    jmnp08 said:
    I am going to say no. It's silly really. The amount of energy absorption from this would be minimal. It could, potentially decrease the chance of sustaining a laceration from a blow. That being said it would be very much used against you. Long hair on any body area is a grip.

    At the same time, the beard is in the front of the body (it's not like head hair), so if your opponent grabs your beard, they are (1) in range and (2) have one less arm to attack/defend with while you have 2.

    Beards may also distract from grabbing head hair. Grabbing head hair is worse because you can pull it back and control the opponent's whole body--with a beard not so much since it is in the front--it's more like grabbing a shirt collar, and your opponent will focus on your beard and not your head hair, and so you'll be in a better place than if the opponent grabbed your head hair.
    Reply