Knuckle sandwich: did fist fights drive evolution of human face?

Jun 14, 2014

By Will Dunham


Current theory about the shape of the human face just got a big punch in the mouth.

Two University of Utah researchers proposed on Monday that the face of the ancestors of modern humans evolved millions of years ago in a way that would limit injuries from punches during fist fights between males.

Their theory, published in the journal Biological Reviews, is presented as an alternative to a long-standing notion that changes in the shape of the face were driven more by diet – the need for a jaw that could chew hard-to-crush foods such as nuts.

“Studies of injuries resulting from fights show that when modern humans fight, the face is the primary target,” biologist David Carrier said. “The bones of the face that suffer the highest rates of fracture from fights are the bones that show the greatest increase in robusticity during the evolution of early bipedal apes, the australopiths.”

These are also the bones that show the greatest difference between women and men in early human ancestors and modern humans, Carrier added.

In both apes and humans, males are much more violent than females, and most male violence is directed at other males, Carrier said. The violence underpinning the need for a more robust facial structure may have involved fist fights over females, resources and other disputes.

26 comments on “Knuckle sandwich: did fist fights drive evolution of human face?

  • 1
    inquisador says:

    So the evolutionary trend in humans, from our pre-human ancestors onwards, is increasing aggressiveness and pugnacity.

    Now we reach a more worrying phase of that continuum; that of growing conflict zones around the world, armed with weapons of increasing destructive power.

    From fist fights to mass self-extinction?

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  • That’s such a negative outlook that doesn’t fit the evidence, inquisador.

    Human society has, rather, become less and less violent the more we’ve modernised. Even if you factor in the great wars of the 20th Century, as a percentage of human population their casualties were not as great (or, at least comparable to) many previous such wars throughout human history.

    And I really don’t think there are growing conflict zones around the world at all. Just because we now have an international news media that tells you about everything as it happens, doesn’t mean more is happening. It just means you know about it more.

    Anyway. This is a piece about how we evolved in the past. Extrapolating that to how we continue to evolve, in a world that’s incomparable to the one our stone-age ancestors lived in, makes no sense.

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  • Violent? OK but I don’t buy this theory. If Australopiths used wood or stone weapons the main target would be the left side or back of an opponents head both of which are much more fragile. The sexual dimorphism of human skulls shows heavier features in males generally, for example the external occipital protuberance is much more pronounced in males than females where it is almost absent. How does their theory account for this?

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  • You’ve obviously never witnessed a violent fist fight. I grew up and spent most of my early adulthood in a place where fist-fighting is the norm — so much so, in fact, that it’s almost an expectation. I’ve witnessed scores of brutal fights and (not proudly) been in a few, myself. I can tell you from first hand experience that it is indeed possible to break bones in the skull (particularly the orbits of the eyes) without breaking your hand.

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  • I agree with Aaron. It’s easy to break the skull with a well placed hit. Think of how easily the nose can be broken. With the older skulls, the zygomatic archs are very prominent and flared. Those could be easily broken or fractured in a fight, especially since the homo sapien precursors were physically much stronger. And once they are broken or fractured, it would become very difficult to eat or use their jaw without pain, possibly forcing them to almost starve until it healed, at which point they would be one of the weakest males, unable to hunt because of no stamina, and unable to hold their own in fights at which point they could be killed in a fight or just ignored because they were no longer useful as a hunter.

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  • Is there a link to the whole article from here?

    This idea is not far fetched at all. When I took A&P, my Prof was also the medical officer at the local prison. When we did the unit on skull and facial bones he stated that Hollywood movies give people the impression that males can punch away at each other indefinitely and get knocked down and keep getting back up to give and take more punches to the head and face. In reality, facial bones are more fragile than most people realize. A well placed punch to the face will knock an opponent backward and the nasal bone, jaw, zygomatic arches, maxilla will break quite easily.

    I may be the only female that comments on fighting here, but I was the only girl growing up in a neighborhood of guys for 18 years and I had opportunity to watch fights almost every day. Of course we protect our face as a priority. An unexpected punch straight to the face is about the worse thing that could happen in a fight. You would definitely go flying and the damage would be devastating. The only thing worse than that is to be cold cocked from behind. But in a one on one fight that has built up momentum from an argument beforehand, defense to the face and front of head is priority. A punch to the side of the head or to the forehead can actually be effective in knocking the person down to the ground where he will get pummeled very badly. When someone’s head is jolted to the side or back in a violent force then usually the rest of them follows. When I had to defend, I always went for the nose as soon as I had a clear shot. This takes much less arm strength and it turns into a bloody mess immediately. I bought some time to run for it that way. (Females need special coaching to defend against male physical aggression)

    If I could modify human facial bones with the knowledge that many fights were to come, I’d:

    Beef up the brow ridges-loss of eyesight would be devastating.
    Same with the zygomatic arches-they are very fragile and their overarching shape leaves nothing solid behind them. The maxilla behind them isn’t robust either and is easily broken when the arch shatters.
    A bulked up mandible could only be a good thing since plenty of punches land exactly there.

    Oh, look at that. It seems like the Neanderthals have beat me to it!

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  • I can believe this theory. Especially looking at the shrinking of the zygomatic arches between the skulls. A well placed punch can easily break a nose or eye orbit in modern humans, because that’s what is prominent and within reach. On the earlier skulls, the main target would likely be the arches, 1) because those are large and one of the first things that would be hit, and 2) because breaking those would do the most long-term damage. A broken nose or eye orbit is little more than an inconvenience. A broken zygomatic arch, however, could be life threatening. The arch is what your jaw muscles attach to. If the arch becomes broken or fractured, it would become extremely painful to use the jaw in any capacity as the muscles would be constantly pulling on the broken bone. This could eventually lead to starvation. Even if the person managed to get enough to eat to survive until their jaw healed, they would most likely be emaciated and weak, and unable to hunt or defend themselves. In a time when the ability to hunt more than likely helped to determine worth and standing, losing that ability would severely reduce their standing, possibly forcing them to become a loner with even less chance of survival. While this is worst case scenario, a broken jaw back then was no small matter. As the arches became smaller, so did the risk of this happening.

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  • 10
    justintc says:

    I can confirm this. I got into several fist-fights during highschool and it’s very possible, almost easy, to fracture the zygomatic process, the orbits, the jaw.

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  • Could the neanderthal, who modern “feminists biologists” tout as “matriarchal and peaceful” – have been the most violent ape?

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  • If you want to have a productive discussion that’s great. Seems like you’re here to snipe though. Why not go over to one of those “mens’ rights” sites if you want to bash women. You’ve placed two comments here that are useless at this point. Up your game will you please?

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  • From the article:

    Carrier said anthropologists have thought the new facial traits in the first bipedal apes were the result of a diet that included very hard objects, and the biomechanics of eating such food can explain many of these features. But he said recent analyses of wear patterns in teeth suggest most of these creatures did not eat hard objects.

    Ok, now that I’ve read the whole article – Thanks for help from bonnie, I now realize just how much Carrier is actually tossing onto the crap pile.

    Let’s see what Lieberman and Wrangham, both at Harvard have to say about this. Evolution of the Human Head by Lieberman is a brain candy tome of fascinating discussion of this very topic. Wrangham’s book, Catching Fire deals with food and cooking and the changes in us that resulted from that.
    “These creatures” didn’t eat hard objects? Like nuts for example? Both of these guys claim that it was constant chewing of raw veg and meat that is responsible for the big, very strong jaw muscles and mandible bone formation.

    Let’s see how this one plays out.

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  • When I hear some folks here, they give me the impression to be masters in fist-fighting. I must have lived in some kind of paradise because I almost never experienced such level of violence in my neighborhood.

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  • You’re lucky. In the nice suburban town where I grew up we had a hoard of teens with too much free time, no parental supervision because they were all working, money in their pockets and raging hormones. It was Lord of the Flies every day during and after school. Fighting wasn’t the worst of it. I learned a lot about male aggression in those years. Female aggression was in college but that’s a whole other (scary) story.

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  • This makes instance sense and may allow light to fall on another attribute of humans. Is it possible the hair on our heads may have a function in reducing the rotation of our skulls when experiencing a blow to the head?
    This would apply to the hair on the jawlines of males as the main, but also easiest, way of inducing concussion to a brain is to rotate the head with a blow to the jawline.
    Hair reduces the friction of the fist against the skin and makes surviving a whack more likely.
    It makes more sense now that males have the hair on the jawline as they engage in more rough play amd physical competition than females.
    The importance of rotation of the skull and brain in regard to brain injury has come to the fore in recent years via the debate over the efficacy of bicycle helmets. Originally helmets on WW2 motorcyclists were found to save brain injury due to the slings and hatbands within them and their hard frictionless shells but modern day cycling helmets are made of foam and have fluting thus providing enough friction to actually exacerbate rotation increasing the likelihood of a local injury becoming a global one.

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  • I’m reminded of the other extreme reported by Ronnie Corbett, where he said that his school was so soft, one could start a reign of terror with a balloon on a stick.

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  • Great comments LaurieB!

    Does this mean that as we move into the information age and women choose to breed with more, “geek”like men that this physical advantage will be watered down over time?

    Also currently in Australia 33.3% of women have experienced physical violence since the age of 15 (just to give an example). Men hitting women is common so why don’t we have the same skull protection?

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  • haha. Hi Kirsty. Very funny about “geek men”

    This is my favorite topic here. We’ve had many interesting discussions on the old site re: male vs female reproductive strategies.

    If women count material resources as a valuable commodity that men control and share with a select few, then it’s not surprising that geeks are seen as desirable partners in the repro game. However, no reality based thinker would claim that women are monogamous and here’s where that hunky, hairy brute with serious upper body muscle mass comes in handy. Key phrase: serial monogamy with occasional forays outside current relationship. One thing I’ll say about those geek men and their women, they seem to make enough money to shelter themselves from the crude physical aggression of those previously mentioned brutes. I guess the physical advantage IS getting watered down.

    One thing about the big 3 religions- men have made a bargain with each other to distribute females amongst them “fairly” and created rules about how this should work (monogamy). When other guys break their rules then there are predictable consequences (law) and in this way, they hand over the violence and retribution to the state. No need to attack hunky Joe Schmo down the street because he did the dirty deed with his wife, the divorce court will punish the relevant parties. Why risk smashed zygomatic arches and put ones self into a year of reconstructive surgery when the court will strip that other guy of at least 50% of his financial assets?

    We (women) can’t win in physical violence against men. I knew it in my late teens back in the neighborhood. I could hold my own in physical disputes until the guys hit 16 or so. There was a very sad tipping point where I couldn’t win and couldn’t even break even against them. My whole strategy shifted to something that I could count on.

    I don’t need extra skull protection. I have something better. Psychological manipulation.

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