According to a new book, the human overbite developed at different times, in different places — and was always coincident with the widespread use of eating utensils. In Europe, for instance, evidence suggests that humans have only had an overbite for about 250 years.

  • tylerkaraszewski

    Taken to its logical conclusion, shouldn’t a paleo diet have us eating nothing but primordial soup?

    • http://pulse.yahoo.com/_SJHMAVJU64JACPSKFSQ5QPEMWQ blank blank

      As long as we don’t use utensils!

  • http://www.facebook.com/profile.php?id=673251060 Ryan Brown

    I tend towards an under-bite… what does this mean!?

    • Jerril

       A bit of the Hapsburg bloodline in you?

  • Nagurski

    Professor Lamarck concurs with this opinion. Really, what twaddle. The “clincher” being that the same change occurred in the Chinese 1100 years ago because of the adoption of chopsticks. Chopsticks were first used like 4000 years ago, and supplanted other utensils. 

    • Kirby_G

      According to that bastion of scientific accuracy, Wikipedia, the earliest evidence of chopsticks is 1200 BCE which makes them just over 3000 years old.  They started to be used for eating in about 200 BC, and not until 1300-1600 AD were they in “normal use” for serving and eating.

      http://en.wikipedia.org/wiki/Chopsticks#History

      • Nagurski

         You can argue about exactly when they became popular, but Chinese had forks and spoons as well, so the utensil theory is absurd, besides there not being any scientific mechanism to support this fantasy.

        • Antinous / Moderator

          Do you have anything to add besides unsupported invective?

          • Nagurski

             See below. The burden is really on the person advancing an explanation for a phenomenon to put up some evidence.

            Here’s a study showing the same sort of change over an even shorter, more recent period, from 1870-1970. http://link.springer.com/article/10.1007%2Fs12548-010-0038-4?LI=true
             It could be due to the development of the hyperspoon or the superfork. Or aliens dicking around with us, or petunias. Anything’s possible, especially when you don’t have to put forward any evidence.

          • Ashen Victor

             Petunias! I knew it!

        • AnthonyC

          As the article quite clearly states, this can’t possibly be an evolutionary change (if the hypothesis is correct). Rather, it would be a developmental consequence of eating w/ utensils- it’s aboout how the jaw grows in the presence of stimuli different than the ancestral environment.

    • dragonfrog

      Read TFA – no evolutionary mechanism is posited.

      It’s suggested that how we eat affects how our facial muscles develop, which affects the position our jaws return to comfortably when we relax those muscles.

      Chairs don’t cause our children to be born with poor posture by Lamarckian mechanisms either – but we still send them off to school, where they’re made to sit in chairs, which affects their posture as they grow up.  Same deal.

      • Nagurski

        I did read the lame article. No citations or other evidence, other than ‘gee whillikers, this happened, because of…’ his assumptions, I presume. Really, food was cut up into small pieces for table in the Shang, nearly 4000 years ago.  But then, chopsticks! And you’re implying that poor posture is universal amongst cultures that use chairs. Also presumably absent from those without. I’d like to see some shred of evidence on that one, too. 

        There are cultures that mainly eat with their hands. Are there big morphological differences in their bite? From this hypothesis, the answer should be, of course.

        • dragonfrog

          Agree with it or not, your remaining objections have nothing to do with Lamarck.

  • http://twitter.com/kpkpkp Kevin Pierce

    What about the jaundice?

  • http://glitch.tl/ Michael Smith

    I don’t see how we could evolve anything in 250 years except possibly partial immunity to a powerful infectious disease.

    • Boundegar

      Nonsense, the thesis is totally plausible, if, for example, utensil-users exterminated all children with an underbite. Evolution can move pretty fast with human intervention.

      • http://glitch.tl/ Michael Smith

        if, for example, utensil-users exterminated all children with an underbite

        Then the “no underbite people” would be currently occupying a small country somewhere like the middle east and fighting anybody who looks at them the wrong way.

        We are not simple.

        • Frank Lee Scarlett

          I think that was the War of the Spanish Succession. The Hapsburgs were the winners in the short heat Evolutionary Underbite Event.

    • dragonfrog

      FTFA:

      This change is far too recent for any evolutionary explanation. Rather, it seems to be a question of usage. An American anthropologist, C. Loring Brace, put forward the thesis that the overbite results from the way we use cutlery, from childhood onwards.

      The idea is that we are born without an overbite, and our facial muscles adapt in each new generation to the use of utensils (if we are raised to use them) by holding our jaws in an overbite position, or to eating without utensils (if we are raised not to) by holding the jaw without an overbite.

      You can probably position your jaw in a non-overbite position just fine now, but you’ll feel a stretch in your jaw muscles. I guess the idea is that if you had eaten since childhood without utensils, your facial muscles would have developed differently, so the relaxed position would be straight-on, and you’d feel a stretch if you held your jaw in an overbite.

      By the same token, chairs didn’t cause us to evolve heritable poor posture, but our cultural habit of spending all day sitting in them is giving each new generation poor posture starting at school age.

      • Antinous / Moderator

        Some day maybe we’ll evolve to read before commenting, but I’m not optimistic about it.

      • Jerril

         The problem I have with this theory is that the shape of our teeth wouldn’t be affected by this.

        There’s a distinct difference between a real overbite, where the molars and premolars don’t mate properly and chewing is impacted, and this fantasy overbite, where somehow everything magically lines up anyways.

        Then, there’s the thing where the two central front incisors tend to be longer than the flanking pair (which prevents the jaw from closing properly at all).

        Our canines are also not placed to interlock properly with the incisors surface-to-surface, and frankly our dentition is different from the other great apes in so many more dramatic ways that picking on the way our incisors line up seems to be missing the forest from the trees.

        Unlike the other great apes, our teeth are strongly adapted to omnivory – our molars and premolars are often cited for their superior efficacy in chewing meat. The fact that our front teeth are different as well should surprise no-one.

  • http://twitter.com/MoonpieNobot Moonpie Nobot

    Seems to me it’s more likely a result of keeping more of our teeth in our mouths. 

  • http://marjaerwin.livejournal.com/ Marja Erwin

    “Us”?

    “Us all”?

  • seanmchugh

    One interesting experiment mentioned at the end of the article was that rats eating highly processed soft food pellets gained more weight than rats eating harder pellets of identical energy content.  She then says, “When we eat chewier, less processed foods — a raw apple rather than apple puree — it takes us more energy to digest them, so we receive less energy.”  I don’t think that’s quite right.  Instead, I think the difference is that more highly processed food (by a mouth or machine) presents more surface area to the digestive fluids which increase the rate of decomposition.  Conversely, if one is trying to loose weight, he should consider swallowing his food whole since a significant portion is likely to pass through without being digested completely.  

    • dragonfrog

      I’d have thought the mechanism would just be that it takes less effort to eat, so we eat more and faster – there’s a delay between being full, and feeling full, so the more effortful our food is to eat, the less we eat during that delay, and the less we overeat.

      • seanmchugh

        I agree, that’s the conventional wisdom, to which she’s probably referring.  But an experiment could decide for us: Two rat populations eating same calories but one highly processed (liquefied) food, and another moderately processed (chunky) such that there is no difference in the masticating effort, which could be verified by measuring that the feeding duration is the same in both cases.  I contend that population eating chunkier food will digest less of it and gain less weight.  And their feces will be heavier.  Anybody care to undertake this experiment?

  • surreality

    What explains those of us who had underbites? I had some orthodontic nightmares fixing that… Must just be a fluke, I guess, or not-so-great jaw muscles. Thoughts?

    edit: not actually sure it’s applicable, since the author mentions changing from an “even” bite to an overbite, but it’s still interesting to think about.

  • legsmalone

    I just read about this in “Consider The Fork” by Bee Wilson. I think it’s an interesting idea, but having learned about this study from such a complete waste of a book I have a hard time taking it seriously. I am seriously considering publishing a supplementary readalong just to keep foodies from getting dumber.

  • John Verne

    “…we will probably never have definitive proof that the overbite results from the adoption of the fork…”

    This is the thing. We have to be careful of stories that sound good. This is a good theory, and perhaps the best one, but we will never really be able to prove this.

  • pjcamp

    So you’re saying Michelle Obama holds her spoon upside down?

  • Aurvara

    I remember reading once about one hypothesis that it was increased starch and carbohydrate in the diet that caused the overbite in the Anglo-Saxon. Apparently before 1066 the Anglo-Saxon bite was edge to edge. I don’t claim this is the correct explanation, just that the dates don’t line up. This idea says it was only 250 years ago the change happened in Europe while the previous claimed evidence from about 1000 years ago.

    Without any strong evidence they both seem ‘just so’ stories.

  • macegr

    So eventually, we’ll be shoveling food into our gaping, open neck-holes fringed by useless vestigal jaws.

    • Antinous / Moderator

      Like Canadians?

  • Nword

    This completely ignores the presence of things like pacifiers and thumbsucking, which I’m sure have absolutely no influence on the way your teeth grow in..

    This sort of thing is just about a perfect example of taking the correlation and running. 

  • MollyMaguire

    Weston Price first had inklings of this association back in the 20′s although as I recall he thought that malocclusion resulted from malnutrition, but others have studied this more recently. Here’s a good summary:

    http://wholehealthsource.blogspot.com/2009/11/malocclusion-disease-of-civilization_24.html

    The main different idea is that the use of utensils is irrelevant. The strongest predictor of occlusion is the toughness of the food being eaten.