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This is why I could never be an anthropologist

Somedays, it’s just awful to have the mind of a 12 year old boy. So I’m reading this serious and interesting paper on Neandertals, and learn something new.

Two particular characteristics have received considerable attention; pronounced humeral diaphysis strength asymmetry and anteroposteriorly strengthened humeral diaphyseal shape. In particular, humeral bilateral asymmetry for cross-sectional area, and torsional and average bending rigidity, appear exceptionally high in Neandertals (averaging 24–57%) compared to skeletal samples of modern Holocene H. sapiens (averaging 5–14%).

That’s science-speak for “Neandertals had massively muscular right arms compared to their left.” And my mind went right into the gutter.

Anthropologists had their own less juvenile explanations: their strong right arms were a response to extreme muscular activity of repetitive thrusting (ack, back into the gutter) with long, heavy spears (slap me hard.) The paper, though, analyzed muscular activity in experimental subjects who made spear thrusts while hooked up to loads of instrumentation, and discovered that, contrary to their expectations, it was the left arm, the off hand, that carried the largest load in stabilizing the thrust. So that hypothesis simply doesn’t work.

So they tested an alternative explanation, and it wasn’t the first one that leapt to my mind. One of the most common kinds of tools found at Neandertal sites are scrapers —if you’re using hides for clothing and shelter, there is a lot of processing involved — prolonged, repetitive scraping motions while stripping excess flesh from the underside of skins. I imagine scraping a mammoth skin is a huge endeavor that does involve a lot of work. They reviewed ethnographic studies, and discovered that processing a single cow hide, for instance, takes 6-10 hours of work. So they hooked up their test subjects to instruments and measured muscle activity during scraping…and it matches, generating forces that could lead to a build-up of muscle and bone in the right arm.

Unfortunately for my adolescent Neandertal wanking hypothesis, though, the comparison probably doesn’t hold up. Even the most obsessive individual is going to be hard up to maintain 6-10 hours of constant activity. Rats, I guess I’m not going to be making a novel contribution to anthropology. Besides, I imagine this guess was made many times before, and for some reason never made it into print.


Shaw CN, Hofmann CL, Petraglia MD, Stock JT, Gottschall JS (2012) Neandertal Humeri May Reflect Adaptation to Scraping Tasks, but Not Spear Thrusting. PLoS ONE 7(7): e40349. doi:10.1371/journal.pone.0040349.

Comments

  1. says

    Even the most obsessive individual is going to be hard up to maintain 6-10 hours of constant activity.

    Speak for yourself, lightweight.

  2. infraredeyes says

    contrary to their expectations, it was the left arm, the off hand, that carried the largest load in stabilizing the thrust.

    It’s perfectly simple: the Neanderthals must have been left-handed.

    [You're welcome.]

  3. pinkey says

    Unfortunately for my adolescent Neandertal wanking hypothesis, though, the comparison probably doesn’t hold up. Even the most obsessive individual is going to be hard up to maintain 6-10 hours of constant activity.”

    Sounds like a challenge…

  4. says

    I read that Neandertal story earlier today and for once I can honestly say my mind didn’t wander over into gutter territory. I actually hadn’t thought about that untill you brought it up, PZ!

    Regarding Neandertals, though… I thought we had established they were black, ape-like cannibals raping and murdering every ice age vertebrate you can imagine? What is this nonsense of tools, scraping and making clothing? Surely they were mere savage beasts!

  5. says

    “Scrapping the mammoth skin” has to enter the American lexicon. I don’t want it to have any specific meaning.

  6. Synfandel says

    @infraredeyes (#3)

    That was my first thought. Who says Neanderthal were right-handed?

  7. tubi says

    @9

    That was my first thought. Who says Neanderthal were right-handed?

    That was my reaction as well. I wonder if the researchers found a certain percentage of specimens with the unblanced condition in the left arm rather than the right. Is left-handedness a modern feature, or did it exist in earlier homonids? Does anyone know?

  8. Ogvorbis: Dogmaticus sycophantus says

    Maybe all social dominance situations were settled through arm wrestling. Now all we need to do is find a Neandertal table with two upright knobs for off-hand gripping.

  9. Dick the Damned says

    Jumpin’ Jeezus, you’ve all leaped to the wrong conclusion. It’s pretty darned obvious that modern Holocene H. sapiens had weak right arms because their teenage boys weren’t wanking. Duhhhh!

  10. Onamission5 says

    @tubi #11–

    And how cool would it be if the trait of lefthandedness was found out to be connected directly to remenants of neandertal DNA? Just speculating based upon the speculation that maybe they were left hand dominant.

    @PZ– I am fairly sure that the force necessary to scrape a mammoth skin clean, when applied to the nethers, would result in a rather painful injury of appendages in that region.

  11. Gaebolga says

    Besides, I imagine this guess was made many times before, and for some reason never made it into print.

    Dear Pentcave,

    I never thought I’d write a letter like this, but….

  12. Menyambal --- Sambal's sockpuppet says

    If I was scraping a mammoth hide, I’d be switching hands, or using both at the same time.

    Long ago, I worked at a travelling carnival, running one of those swing-the-hammer-ring-the-bell games. As a scrawny lad, I couldn’t ring the bell, which looked bad to the customers. I worked out a flashy one-handed sweeping approach that developed much momentum. By the end of the summer, I was decidedly lopsided. (Yes, I controlled for wanking.)

    I suggest that the Neanderthals used a wooden club or something, just like in the funny papers, instead of a`spear. Especially if they were hunting animals for their hides.

    A thrusting spear is a two-handed weapon, as nobody should have had to be told.

    (BTW, the “thal” syllable in “Neanderthal” is related to the “dol” in “dollar”. That doesn’t make up for the “In God We Trust” stuff on the dollar, but I find it amusing.)

  13. says

    @tubi #11

    The language hemisphere is that opposite to the dominant side,
    if I remember correctly, and that leaves distinctive marks
    on the inside of the skull. I have a vague recollection that
    “in prehistoric times” (yeah, vague), left-handedness was more
    frequent, but still the minority case (20% or something).

  14. plutosdad says

    This is anecdotal: but if you look at bodybuilding websites, you will see a lot of men complaining that their off-hand arms are bigger. The hypothesis is since so much of muscle-lifting is neural, that your handed-hand is very efficient. The off-hand is less efficient, and builds up more muscle to perform the same task (lifting dumbbells hoping to get exactly equal arms).

  15. madscientist says

    Well, we should still observe this phenomenon in many contemporary native tribes from North to South America. But perhaps the Neandertals were so silly they only used one hand to hold the scraper and never realized that they could use two hands? Another alternative: they liked to rest by hanging from trees by the right arm. Yet another: they were predominantly left-handed spear throwers.

  16. The very model of a modern armchair general says

    the “thal” syllable in “Neanderthal” is related to the “dol” in “dollar”.

    And what does that syllable mean?

  17. Gnumann, quisling of the MRA nation says

    the “thal” syllable in “Neanderthal” is related to the “dol” in “dollar”.

    And what does that syllable mean?

    My rethorical-question-detection device is off the wonk, so I’m just going to assume this isn’t one. Thal is the same word as English dale, dollar is derivative of the same word, and AFAIK the supposed word “dol” has never been used (at least not in any way leading to the word dollar).

  18. says

    I remember reading about Rod Laver, and the reporter said that sitting on Rod’s right side looked like he was sitting beside a powerfully built person, as opposed to sitting on his left with the appearance being of a slightly built man.

    The neanderthals played tennis!

  19. ah58 says

    An easy way to support the wanking hypothesis would be to check if male neanderthals spine show an abnormal amount of curvature. Hairy palms would be another piece of supporting evidence but may be a bit harder to verify in the fossil record…

  20. Menyambal --- Sambal's sockpuppet says

    The “thal” in Neanderthal is from the German for valley (New Man’s valley—funny story below). Another valley—Joachimsthal—had a mint that made coins that were called “Joachimsthalers” which was shortened to “thaler” which was corrupted to “dollar” by the time it got to English. The syllable “dol” wasn’t on its own—sorry to give that impression.

    Neanderthal: A German scholar named Neumann decided to get all pastoral, and found a little valley, a “thal”, to think lofty thoughts in. He Latinized his name to Neander, which meant “new man”, and the valley became known as “Neanderthal”. He may have hoped to develop a new kind of humanity, but when the quarry in his valley yielded the bones of Neanderthals, they got his name.

  21. robro says

    Isn’t there something about medieval warriors developing such asymmetry? As I recall, some historians speculate that Richard III’s deformity was the result of wielding the sword. (Personally, I favor the idea that the deformity was propaganda.)

    I agree about the one-hand, two-hand scenario. They surely used both hands at times, but perhaps they used the stronger hand somewhat more. Even when pared they might have given more force with their strong arm and used the weaker one for controlling the material.

    As for hides as clothes, this suggests an interesting alternative:

    http://www.nytimes.com/1999/12/14/science/furs-for-evening-but-cloth-was-the-stone-age-standby.html?pagewanted=all&src=pm

  22. Menyambal --- Sambal's sockpuppet says

    If the Neanderthals were making string, they could have made slings. Slings, contrary to popular belief, can be used to chuck some pretty heavy rocks using arm muscles and the whole body, not just a twirly wrist action. Accurate slinging takes a lot of practice, and would lead to asymmetry.

    I propose that possibly Neanderthals used clubs, as I said above, and carried a leafy branch or something as camouflage in the left hand. A patient sneaking up into club range, then a swift clonk over the head.

    The asymmetry would develop with constant practice with the club.

    I want a hunting scenario that fits with the image of Neanderthals as slow and heavy. I can’t picture them bounding over the plains in a persistence hunt to get within stabbing-spear range.

    I cannot see a hunting method that develops asymmetry while hunting—how often do you need to stab a mammoth to kill it? But I don’t like asymmetric working, either. I argue for deliberate practice or body building techniques.

  23. ChasCPeterson says

    Neanderthals were crazy about baseball and they all wanted to pitch. (There is some evidence from crude cave-painting box-scores that they perfected the knuckleball. Cro-Magnons were suckers for the knuckleball.)

  24. Azkyroth, Former Growing Toaster Oven says

    An entire thread dedicated to wanking jokes?

    It’s a real circle-joke here, with everyone joking off…

  25. Ysanne says

    About the Neanderthal vs. Dollar thing:
    Dollar is a somewhat evolved pronounciation of the German word “Taler” or “Thaler” (depending on spelling), the name for a large silver coin. The first of its type was named after its silver mine in, Joachimsthal (“Valley of Joachim”), followed by coins made of silver from other valleys that were called <ValleyName>thaler, and at some point the coins’ names were just generalised to Thaler.
    This name has spread to a lot of languages in different spellings and variants, from Scandinavian “daler” and US “dollar” to Hungarian “tallér”.
    Wikipedia has a lot about technicalities and history in the “Thaler” article.

  26. jakc says

    I think, in general, that the evidence indicates that Neandertals were as strongly right-handed as modern populations. Chimps and some other primates show some hand preference, but not as much as humans.

  27. F says

    22

    Yep: “Valley”. (And dollar comes via thaler).

    Part of one of my favorite words: thalweg.

  28. Feline says

    If I was scraping a mammoth hide, I’d be switching hands, or using both at the same time.

    True, but at least the last time I was scraping a hide with a bit of flint I mainly pushed forward with my right hand and mostly pushed down with my left in order to keep the flint (more or less) level. There was a definite difference in how much I worked my right arm compared to my left.

  29. Menyambal --- Sambal's sockpuppet says

    Thanks, Feline. I’ve never scraped a hide. I suppose if they used a lot of hides … hmmm—that might be what brought them into that area: somebody figured out how to tan hides, and suddenly they had clothes and tents and waterbags, and needed even more hides.

  30. Snoof says

    He Latinized his name to Neander, which meant “new man”

    Hellenized, I think. “Ander” is Greek; the Latin equivalent is “vir”.

  31. pacal says

    Pentatomid said:

    Regarding Neandertals, though… I thought we had established they were black, ape-like cannibals raping and murdering every ice age vertebrate you can imagine? What is this nonsense of tools, scraping and making clothing? Surely they were mere savage beasts!

    Got the book. (Them + Us by Danny Vendramini) It certainly made for an exciting story! However all it is is a good story. The nonsense that litters almost every page is amazing. Hell the guy even tries to bring back Lamarkism with an absurd notion called “teems”. The book’s view of Neandertals is simply over the top silly. The reconstruction of the nose is esspecially funny. It is ironic that the guys bibliography is half decent but it is pretty obvious he cherry picks and distorts the information found in there and further deliberately ignores vast amount of data that makes his hypothesis very unlikely to put it mildly.

    I should point out the author does admit that Neandertals made tools, and made spears, although he denies they wore clothes. He doesn’t even try to explain all those scrapers found in Neandertal sites. Why all this attention by Neandertals to scraping skins if they didn’r wear them?

    It is such a pity because desperately trying to get out of the mess the book is is a good book about the “prey” hypothesis. However instead of rapist, apish Neandertals, who seem to owe more to horror movies than reasoned science, it would have been lots and lots of big cats, large dogs, giant hyenas etc. The idea that early man was prey to these large and very dangerous predators and this shaped early human evolution is a interesting one. However this book reduces it to the plot of a bad horror movie with a horror movie vilian.

  32. Menyambal --- Sambal's sockpuppet says

    Hellenized? I have learned a lot here, some of which is not to trust old memories, and to use the internet to check facts.

    The internet tells me that “tal” is the new spelling for “valley”, but the species was named back when “thal” was the word, and the name doesn’t change. I don’t know how, if at all, the pronunciation changed.

  33. krubozumo says

    mikmik – somebody has probably already pointed it out but Laver was a southpaw and his left arm was noticably bigger than his right, your statement is a bit ambiguous so I will let it go at that.

    Mostly I am just testing that I can comment again.

  34. Amphiox says

    IIRC, one hypothesis about the predominance of right-handedness in humans (as opposed to other living primates where if there is hand preferences, it is usually closer to a 50:50 split) is that it is a sequelae of specialization of the left hemisphere of the brain for language function.

    An implication of this finding is that the Neanderthals had predominance of hand preference, which in turn suggests hemispheric specialization, which in turn suggests that Neanderthals had language capability equivalent to H. sapiens.

    And if Neanderthals were predominantly right-handed, that would suggest that hemispheric specialization for language capability evolved before their split with our mutual common ancestor, and that our common ancestor had it too.

    If Neanderthals were predominantly left-handed, however, that might suggest that they evolved hemispheric specialization independently, in which case they might have evolved language independently too (or, alternately, they evolved hemispheric specialization for something else other than language).

    However, it should be noted that if the left handed hypothesis is true, the physical changes associated with hide scraping should also be switched, to favor the left side, but this was not observed. This argues against Neanderthals being predominantly left-handed as an explanation.

  35. Gnumann, quisling of the MRA nation says

    However, it should be noted that if the left handed hypothesis is true, the physical changes associated with hide scraping should also be switched, to favor the left side, but this was not observed. This argues against Neanderthals being predominantly left-handed as an explanation.

    If I read people correctly, the left/right speculations are mainly based on the premise in the paper that a spear thrust places more stress on the off hand.

    Personally, I think the whole focus on weaponry is a bit off. How much time of the day are you going to be spearing a mammuth? And the hypothesis that muscles come from some long, drawn-out task seems logical.
    Unless of course they trained all day for spearing mammuths. Perhaps not a silly thing to do if you’re going to hunt them.

  36. DLC says

    . . . Picturing PZ sitting in his chair reading this report, and every now and again chuckling . .. “huh-huh, uh huh-huh Hey Beavis, these guys had big right arms ”

    Whoops. wrong 12 year olds ?

    Of course, it could be that Neanderthals liked to show off as a mating ritual and did 1-armed pushups. . .
    ooh, ohh, I know! let’s ask an Evo-Psych !

  37. Philip Langmuir says

    prolonged, repetitive scraping motions while stripping excess flesh from the underside of skins

    My mind also went into the gutter… then things got weird. Very weird.

  38. christophermoss says

    Perfectly obvious to anyone who has made flint tools – it’s not the using that builds the arm strength, it’s the making. Flint takes a lot of knapping, mistakes mean starting again, and they blunt quickly. Neanderthal tools were better made and generally more neatly finished than those from H. sapiens.

  39. Tony the Parkour Kat [safe and welcome at FtB] says

    PZ:

    Even the most obsessive individual is going to be hard up to maintain 6-10 hours of constant activity.

    hard up?
    Really?
    :)

  40. Gnumann, quisling of the MRA nation says

    Perfectly obvious to anyone who has made flint tools – it’s not the using that builds the arm strength, it’s the making. Flint takes a lot of knapping, mistakes mean starting again, and they blunt quickly. Neanderthal tools were better made and generally more neatly finished than those from H. sapiens.

    You might be on to something here. For scraping you might want to use both hands or alternate, but you really want to use you good hand for hammering. For oblivious reasons.

  41. David Marjanović says

    “Scrap[...]ing the mammoth skin” has to enter the American lexicon. I don’t want it to have any specific meaning.

    :-D

    The “thal” in Neanderthal is from the German for valley (New Man’s valley—funny story below). Another valley—Joachimsthal—had a mint that made coins that were called “Joachimsthalers” which was shortened to “thaler” which was corrupted to “dollar” by the time it got to English.

    Yes. Also, the h in Thal was purely cosmetic (probably it was meant to make German look more like Greek); it never meant anything pronunciation-wise and was unceremoniously dropped when the German language got an orthography in 1901.

    Central (and extreme southeastern) German dialects don’t distinguish p, t, k on the one hand from b, d, g on the other; this may explain the d of dollar. The o may be because southeastern dialects, such as mine, have shifted some of their vowels.

    Did Neanderthals have atlatls?

    Nope, though see comment 30.

    It’s a real circle-joke here, with everyone joking off…

    :-D

    I think, in general, that the evidence indicates that Neandertals were as strongly right-handed as modern populations.

    At least there’s simply no evidence to the contrary.

    He Latinized his name to Neander, which meant “new man”

    Hellenized, I think.

    Yes. He skipped mere Latin and went all the way to Greek (which is also friendlier to compound nouns).

    I think, in general, that the evidence indicates that Neandertals were as strongly right-handed as modern populations.

    Or, at least, there’s no evidence to the contrary.

  42. ffrancis says

    The wanking hypothesis depends on the large right arms being characteristic only of male Neanderthals. So too would any of the hunting or tool-making causes (assuming these are still considered to have been predominantly male activities). Does anyone know if female Neanderthals also show this asymmetry? I can’t see any mention of this in the linked study, although it might lend weight to the hide-scraping explanation as that, at least in some hunter/gatherer groups, is not an exclusively male activity.

  43. Gnumann, quisling of the MRA nation says

    The wanking hypothesis depends on the large right arms being characteristic only of male Neanderthals.

    I see someone is narrow-minded…

  44. jayarrrr says

    @Robro- I recall reading the same hypothesis on medieval skeletons with asymmetry in the arms being “proof” that the skeletons in question were archers, because of the strain of drawing the longbows of the era.

  45. Rising Ape says

    Thanks for making my day richer by making me smile with juvenile humor while engaging my scientific curiosity and teaching me something I would probably never have occasion to read myself. Bravo!

  46. Rolan le Gargéac says

    Menyambal — Sambal’s sockpuppet @30

    I can’t picture them bounding over the plains in a persistence hunt to get within stabbing-spear range.

    I am under the impression that the Neanders lived in cold very forested regions ? Ice Age, neh ?

    I cannot see a hunting method that develops asymmetry while hunting—how often do you need to stab a mammoth to kill it,

    Er, never?, dig a big ole ‘ole ?

  47. Rolan le Gargéac says

    Whoops pressed wrong wossname and posted, shazzbat !

    Asymmetrical hunting methods I agree are very difficult to imagine unless you live in a Piers Anthony world, and apparently, we don’t.
    I cannot think of an example in any of the animal – reptiles, fish,insect, etc etc clades that use such techniques. Well the fiddler crab, but, oh dear Lard P.Z. is right !

    I’m going to lie down for a while.

  48. says

    Poor Greg Laden having to keep a straight face during a presentation or critique of this paper.

    So apparently there was no Neanderthal analog to the Fleshlight?

  49. julietdefarge says

    Like other commentors, I’m curious about the sex of these strong-right-armers. There’s no reason why hide-scrapers would be one sex or the other, but probably most of us assume that Neanderthal women worked near the campsite or went out in foraging bands while the men were hunting. I’m going to have a look at early photos of Plains Indian women and see if I can notice anything.