A group of American biologists decided to check whether a beard can protect a man from injuries in a fight, just as a mane protects a lion’s neck from fatal bites in collisions with competitors.
The male beard is an adornment in the most classical biological sense: only one gender has it, appears during puberty, grows big-boiled, and it seems to be of zero benefit from it. Or is there any benefit? Some scientists have been very serious about the biological role of the beard, putting forward various more or less bizarre hypotheses. For example, a beard protects your face from the cold (remember the song: “The beard warms in the cold”?). The question is, why doesn’t the fair sex have such a useful thing? The answer is obvious: freezing is the lot of men. The woman - the keeper of the hearth, sits at home in the cold. Another remarkable hypothesis: a beard disguises a hunter (!) - “blurs” the clear contours of the head, which is apparently useful when looking out from an ambush
The more popular version is sexual selection: a beard is needed either to attract ladies, or to intimidate competitors. And there is something to be afraid of: after all, facial hair visually increases the size of the jaws, and the demonstration of teeth is a typical method of intimidation in primates. Or maybe the task of the beard is to soften blows during fights? Scientists substantiated the latest version by drawing a parallel with the lions. By the way, even Darwin in the Origin of Man told how a mane protected a lion from the bites of a tiger bursting into a lion’s cage in one of the zoos.
Interestingly, that lions are almost the only feline social animals. Cats are known to be great individuals. Only lions unite in prides, sometimes in three or four dozen goals. And it is precisely the lion males, the only one of all cats, to have such a decoration - a mane. Coincidence? Ethologist D. Caroline Blanchard sees the reason for the high frequency of collisions between males, and the cost of losing is high: the winning lion can not only expel a competitor from the pride, but also kill all his kittens. And so, according to the ethologist, he protects the fighting huge cat mane from fatal bites.
It is logical to assume that this is true for men who often fight, and in In fights, the main target is the face of the enemy. According to statistics, men really more often than women suffer from facial injuries. The lower jaw is one of the most vulnerable parts of the skull when struck in the face. A jaw fracture is very painful. It is believed that a massive skull with thicker walls developed in human males, including for this reason: to make it harder to break through. It is noticed that a massive face in men correlates with aggressive behavior and success in sex. And the same is true for a beard: studies by psychologists have shown that bearded uncles look more dominant and intimidating, and facial hair positively affects reproductive success in conditions of high competition. Perhaps the beard plays the role of a shock absorber, absorbing and dissipating the energy of a blow during a “hook” in the jaw?
A group of American biologists decided to test the shockproof properties of the thickets on the face in an experiment . No, they did not grow beards and peel each other. Models were tested: a piece of sheep’s skin covered with wool was placed on a plastic bone imitation. For some reason, the researchers chose the sheepskin as a substitute for the male beard. The authors themselves write that sheep’s hair is thicker and grow much denser than human hair: 1 cm 2 of sheep’s skin is 6000 of the hair follicles, while in a person on the chin - only 60 hair per cm 2 . But human hair, on average, is more than 5 times longer than sheep’s. The authors believe that sheep’s fleece can be considered an “approximate substitute” for the beard, although I honestly am completely unsure of this.
Researchers have made many such samples . Sheep skin was specially impregnated with physiological saline so that it was “live”. The samples were divided into 3 categories: shaved (wool trimmed to a length of 0.5 cm), “epilated” (hair removed with roots) and intact, where the hair was left as is, about 8 cm long. According to the authors, such options correspond to a full beard short bristles and bare skin. The bristles were included in the experiment to check whether hair follicles play any role in protecting against shock.
The experiments were carried out in a special device where the samples were subjected to shock falling cargo. The chipper weighing about 5 kg fell on the anvil from a certain height (5-8 cm). Thus, it was tested 22 samples: by 20 of each category.
Well, the result pleased the experimenters. Hair well protected the “bone” from blows: under the same conditions, they received damage 95% naked, 70% shaved and only 22% hairy samples. Apparently, the skin covered with hair well absorbed the shock, dissipating energy, slowing down the striker and distributing the blow over a larger area (in the words of the authors of the article, in much the same way “bulletproof vest holds the bullet”). At the same time, as we see, the shaved version does not differ much from the naked one, which means that the hair roots do not play a special role in protection.
To this we can add that the beard also protects the skin and muscles of the face from scratches and lacerations, reduces friction during a sliding impact, and so on. Therefore, the researchers believe, the bearded bully received fewer injuries, which means that beard was accompanied by natural selection. In addition, the very appearance of dense thickets testified to the fact that the face is reliably protected. Therefore, the bearded man and the competitors were afraid, and the ladies respected.
In addition, the authors believe that the results of the study speak in favor of the protective role of the mane in the lion. Perhaps, why sheep’s wool does not imitate the lion decoration at the same time? Tinkering with the famous expression, it turned out "a lion in sheep's clothing."
It is possible, the researchers continue, that “specialization in fights” played a significant role in the entire evolution of man. This hypothesis has been expressed before. Short forelimbs, features of the muscles, even the vertical position of the body can be considered as adaptations aimed at improving the "combat characteristics" of hominids. Beard - from the same series.
But what about other experiments in which the advantages of the beard could not be found? One of these studies analyzed the number of knockouts in fights according to the rules of “mixed martial arts” (MMA). Comparing the indicators 556 of such fights, the researchers did not find evidence that the beards at least somehow helped their owners win victories. Scientists then came to the conclusion that bearded men can intimidate competitors with the help of their natural jewelry, but nothing more.
And how is this consistent with the new results? Well, in the new study, this is not about knockouts, but about traumatic blows to the jaw, fractures and lacerations - these are not at all the same thing, the authors of the publication twisted. A professional duel and a street fight dictate completely different rules.
The question remains: why not in all human populations men can boast of thick beards? It is possible that in those communities where only thin beards are found, there was no such strong competition between men, or some other important restrictions showed up - for example, because of the heat, it was necessary to maximize the area of bare skin. Finally, the researchers write, the fact that the beard grows only in men, but does not grow in women, suggests that such jewelry clearly has real flaws. I can not disagree with the last statement.