Just How Long Did Grok Live, Really? – Part 2
Speculation on ancestral lifespan is fun and potentially illuminating, but I think examining living, albeit imperfect, examples of modern hunter-gatherers offers greater insight. Sure, the environment has changed, wild food sources have shrunk in diversity and availability, and modern civilization has encroached and meddled and disrupted, but the few remaining hunter-gatherer populations exhibiting relatively untouched traditional lifestyles represent the most promising window into what life actually looked like and how long it lasted for our ancestors. Luckily, a couple of researchers – Gurven and Kaplan – had the bright idea to look at ethnographic studies on actual, living HG populations and analyze the available data on actual lifespan and mortality therein. They found some interesting stuff.
This study (PDF) has been floating around for a while. Readers have sent it to me on several occasions, and I believe it’s been mentioned in other bits of the online ether (blog comments, etc). The earliest I saw it was over a year ago on Ryan Koch’s blog.
The populations they looked at were given classifications: hunter-gatherers; forager-horticulturalists; and acculturated hunter-gatherers. Hunter-gatherers were groups without significant contact with outside cultures and included the !Kung, the Ache, the Agta, the Hadza, and the Hiwi. Forager-horticulturalists hunted, gathered, and used some agriculture. They included the Yanomamo, the Yanomamo Xilixana, the Tsimane, the Machiguenga, and the Gainj. Acculturated hunter-gatherers/foragers had significant, steady contact with outside cultures and included Northern Territory Australian Aborigines, the Tiwi, and the Warao, as well as other !Kung, Agta, Hiwi, and Ache groups. Gurven and Kaplan also looked at Swedes from the mid 18th century.
On average, 57%, 64%, and 67% of children make it to 15 years among “untouched” hunter-gatherers, forager-horticulturalists, and acculturated hunter-gatherers, respectively. That makes perfect sense, given what we know about child mortality rates in HG populations. The “wildest” groups, the HGs, who rely on hunted and gathered food also experience the most childhood deaths, while the hunter-gatherers with similar diets but presumable access to certain modern trappings enjoy the best childhood survival. It’s important to note that the acculturated groups in this study were characterized by increased access to immunization and medical care, especially for children; acculturation of traditional peoples hasn’t always had such a beneficial effect on their health and longevity (consider the health of Native Americans relegated to reservations, white flour, sugar, and vegetable oil). In fact, first contact with industrial or “civilized” cultures usually resulted in a massive initial increase in childhood mortality (diseases, mainly; the Ache lost about 40% of their population to foreign disease), but post-contact was characterized by lower childhood mortality, even compared to pre-contact rates. Mortality reductions in contacted hunter-gatherers were greatest in childhood and declined as populations aged.
Of folks who hit age 15, the percentage of hunter-gatherers who make it to age 45 is higher than the percentage of forager-horticulturalists who make it to age 45, but not by much – 64% to 61%. Acculturated hunter-gatherers excel here; 79% of their 15 year-olds make it to age 45. You might even say the study’s acculturated hunter-gatherers were essentially Primal, eating and moving traditionally while enjoying access to modern medicine.
From age 45, the mean number of expected remaining years of life is 20.7, 19.8, and 24.6 for hunter-gatherers, forager-horticulturalists, and acculturated hunter-gatherers, respectively. Give or take a few years, they could all “expect” to live about two decades if they were still alive by age 45 – a far cry from a “nasty, short, and brutish” existence.
There was variability among different populations within each category, of course, and at a later date it might be worth it to examine the differences in lifespan and lifestyle (diet, illness, etc.) among, say, the Ache and the !Kung to see if they align with our Primal perspective. The Ache, for example, rely heavily on hunting, traditionally obtain upwards of 80% of their calories from animals, and have high levels of homicide (including infanticide and warfare with rural Paraguayans), and they tended toward greater adult mortality.
The authors have no allegiance to or interest in the Primal Blueprint diet, but we can glean a few things that relate directly to our interests. First, it demolishes the common refrain that hunter-gatherers all die young. Average life expectancy is marred by infant mortality rates, and it’s clear that hunter-gatherers – the closest analogues to our Paleolithic ancestors – can and do enjoy “modern” lifespans with an average modal age of 72 years.
Second, Gurven and Kaplan show that “degenerative deaths are relatively few, confined largely to problems early in infancy.” Heart attacks and stroke “appear rare,” and the bulk of deaths occur when the person is sleeping and are free of obvious symptoms or pathology. Most “degenerative” deaths are attributed to “old age.” “Illness” is the main cause of death among all age groups and all populations, except for the pre-contact Ache (supreme hunters), and the authors break illness into different categories. The big killers were infectious respiratory diseases, things like pneumonia, bronchitis, and tuberculosis. Gastrointestinal illnesses also did a number on them, accounting for 5-18% of deaths, with diarrhea (probably stemming from parasites and coupled with malnutrition) taking the lion’s share. Violence was also a significant killer.
Third, and this is crucial, it destroys the other common argument that an evolutionary diet high in animal products might still be harmful because we didn’t evolve to live past forty, which is when diet-related diseases begin to show. Gurven and Kaplan make an extremely salient point: since the bulk of human evolutionary history took place over the course of 2 million years prior to the advent of agriculture, and that pre-agricultural period conferred most of the “major distinctive features of our species, such as large brains, long lives, marriage and male investment in offspring,” it’s likely that the “age-specific mortality pattern” of human beings also evolved “during our hunter-gatherer past.” That is, they propose that the human potential for longevity is not a product of modern living; instead, it appears to be a genetic characteristic shared by all Homo sapiens. Advances in medical technology bolster and support that inherent longevity (as shown by moderate lifespan increases in acculturated hunter-gatherers and modern industrial populations), but they aren’t responsible for it.
This data shows that human longevity is not a product of modern living. It shows that we have inherent proclivities toward long life, as long as we satisfy certain criteria – namely, the steady acquisition of food and shelter and the avoidance of infection, trauma, illness, and violent injury. The evolutionary lifestyle that eschews modern industrial processed food and promotes healthy levels of activity is the same one that supported our evolution into long-living Homo sapiens. Modern technology, sanitation, and medical advances are merely the cherries on top of an already solid framework.
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Posted By: Mark Sisson
That’s a cool picture!
Dying in your sleep, that has to beat months on end hooked up to modern machines giving you an ‘extra’ bit of lifespan.
Very interesting article, thanks.
Agreed! Great post to, I was under the impression hunter gatherers didn’t live that long, glad to be proved wrong!
Excellent post! I wonder how much infection afflicted human populations prior to the adoption of animal domestication. Jared Diamond has discussed how animal domestication led to an increased transfer of viral infections (e.g., colds, flus, small pox, TB, etc.) from farm critter to human. Prior to the domestication of animals such viral transfers were probably rare. Death from viral infection may have been much lower in pre-pastoral times.
good stuff, as always
Early deaths among children tend to skew the numbers and make the statistics lie. If one person dies at age 2 and another dies at age 80 the average lifespan is 41. Doesn’t give a clear picture of what really happened.
Such is the result of statistics.
Such is the result of using unclear statistics. Statistics can be used in clear, accurate ways…
This is why I never want to hear about “the average lifespan,” but only “the typical lifespan.” Even in PB, Mark talks average. What I want to know is, how long was the typical dude who made it past the age of 20 (& didn’t die by animal or enemy attack) alive and in good health?
Only that will tell us how modern lifespan & health compare to primal lifespan & health.
You say that once a HG reaches 45, they are likely to live for an additional 20.7 years, so let’s say 66 years, then you say that the modal average is 72 years… where did the extra 6 come from?
Chris,
I am guessing this is just statistical jargon accounting for the difference in numbers. The mean (20.7 years in your example) is slightly different from the mode in statistical terms. The mode just throws out the highest and lowest number, then the next remaining highest and lowest until the middle number of the group is found (ie the mode).
So if five people lived an additional 8, 12, 27, 28, and 30 years then the mean is 105/5 = 21 years, and the mode or middle number is 27.
To confuse it a bit more it looks like they took the modal average which I think is a mean of the mode numbers from the different studies.
Bottom line, it is easy to make statistics lie and say whatever you want.
Long live Grok!!!
You’re right in saying that its just a different average but you’re confusing mode and median.
There are three types of average. The most common one and the one most people mean when they say average is the mean. Which is just all the numbers added together and divided by the number of inputs. The median is the middle number that you described above.
If five people lived an additional 8, 12, 27, 28, and 30 years then the median is 27 not the mode.
The mode is the most common number.
If you have average additional lifespans of 8, 12, 26, 27, 27, 27, and 30 then the mode would be 27.
You’re right though when you say that statistics lie. Gotta be willing to sift through them.
Thanks for clarifying. I was just coming back to admit my own incompetence so I am glad to see someone who really understands things explain it a little better…sigh! Damn those pesky numbers!!
Even I dont like all this talk about death lets have more primal snack chat ok?
What an interesting, relevant analysis! Thanks for relaying and summarizing.
And of course recent DNA studies of Egyptian mummies failed to find any evidence of cancers. The discussion suggests that our modern day ailments and illnesses are determined by modern diet and lifestyle.
Interesting, as (IIRC) Egyptians did eat wheat (or something similar to it).
I bet it helped that the Nile was a lot cleaner back then than it is now. They also ate lots of fish, and all sorts of other goodies they could farm along the fertile floodplains of the Nile. Great combo.
So how do I pronounce !Kung? Is that like an unintelligable scream followed by the word “Kung”, or more of a mimed scream and then “Kung”? Or do I just say “Kung” short and stacatto like I’m jumping out of the bushes to scare someone?
Haha I am wondering the same thing! The exclamation mark in front does not make any sense to me.
Can anyone clarify for us curious groks?
The !Kung have one of those languages (http://en.wikipedia.org/wiki/Khoisan_languages) that has clicks in it. Ever seen the Gods Must be Crazy? I don’t think there’s really an equivalent letter in the European alphabet, nor can we even distinguish between many of the click sounds.
The ! signifies a particular type of click sound. Clicks are meaningful parts of word pronunciations, where the presence or absence of a click makes for an entirely different word. Clicks are not found in English dialects.
In fact, clicks are only found in some African dialects (or languages, if you’re so inclined). Some linguists have postulated that the first human language contained clicks. The reason for this is that no dialect without clicks has ever evolved into one with clicks. In other words, over time, as people migrated away from Africa, their dialects lost click sounds, and those clicks never reappeared.
No, not a scream at all. The name of the !Kung is pronounced by clicking the tongue before articulating the ‘K’.
How do I know this…? Thank my many years of watching Sir David. The man is a god – He Knows All and Sees All!
Gosh, I worked this out in a thought experiment (using a few assumed parameters) during a training ride plus a few subsequent scribbles on the back of an envelope.
An interesting aside is the historic decline in violent deaths over time (Pinker). Certainly here in NZ, Maori must have drawn a collective sigh of relief at the demise of cannibaism with the arrival of Europeans,
What comes to mind is that the Industrial Revolution has added 25-30 years to all our lives because we don’t have to work ourselves to death. We also don’t freeze in the winter …
So you think we were working ourselves to death _before_ the Industrial Rev, and not during/after? That’s a new one!
Thanks for tackling such an important topic. Some may not think that vitality and longevity necessarily go together, but it will be interesting to see what kind of analysis ultimately surfaces.
I find the prospect of delaying or avoiding degenerative “diseases of old age” far more enticing than an increase in lifespan.
Mark has just presented some information that agrees with what you want to believe.
This stuff is like a religion .. don’t let the facts get in the way of common sense, knowledge or logic .. just believe!
Real analysis of the data shows earlier civilizations died much younger than we do now …
But if it makes you feel good … keep it up ….
Whatever you do, don’t ask an archeologist or any one who might use real science to explain
It depends what you are defining as an early civilization. Most archaeologists would consider the rise of agriculture the beginning of complex civilizations. Those people were not eating a paleo diet.
“Real analysis of the data shows earlier civilizations died much younger than we do now …”
Uhuh. I’m almost positive that comparison of the lifespans of people living in different phases of agricultural based civilizations wasn’t at all the subject of Mark’s post.
Right, and certainly don’t ask any of the archaeologists or other real scientists that Mark has actually referred to for support in this post or previous posts on this and zillions of other topics.
Heh.
This is a really interesting article. After reading it, I’m wondering about just how accurate these studies are and also what kind of condition these people where in at 45.
The last sentence clinches this post for me.
Here’s an interesting question: Isn’t it the development of organized agriculture, with its concomitant specialization and surpluses, that has led to the development of modern medicine — which, in turn, has reduced infant mortality and deaths from respiratory and gastrointestinal disease?
I’d just substitute “modern medicine” with “higher sanitation standards”. The term modern medicine comprises also many things that work against healthy living. Heck, doctors had been reluctant to even wash their hands before treating patients until the advent of the 20th century.
The point is you cannot isolate all the factors and that we live now and here and should be striving to use the best sources available to live healthy fulfilling lives, regardless of the origin of those sources.
Yes, argiculture has helped us in all sorts of ways that led to the luxuries we call modern civilization. Art… science… industry… medicine…
That doesn’t mean cheap starch calories are also the most optimal calories for us when we have a choice in the matter, though. It just means we had an efficient way to get food and could start living in cities and cooperating in new ways.
How about maternal deaths relating to childbearing? I have always thought that was an important factor in keep average life span down, in addition to childhood mortality rates.
Childbirth wasn’t all that dangerous until doctors insisted on sticking their hands where they didn’t belong, leading to the rampage of childbed fever in the mid-18th to mid-19th centuries, before hand-washing and antibiotics helped lower the incidence dramatically, and allowed modern medicine to claim it had saved all us women from certain disaster.
Weston Price’s work shows birth being an easy process that rarely even involved midwives in some cultures, until their diets changed to incorporate the processed food of civilization. One physician in Alaska said that when he first got there, he almost never got to a birth in time, or was needed, but after 36 years and the daughters of the first generation to eat processed food started having babies, many of them had to be carried to the hospital after hours or days of difficult labor.
Cinnamon and honey. Why does it work/ not work
Quote from that paper:
“There is some variability among groups. Among traditional huntergatherers, the average life expectancy at birth (e0) varies from 21 to 37 years, the proportion surviving to age 45 varies between 26 percent and 43 percent, and life expectancy at age 45 varies from 14 to 24 years.”
So the average life expectance at birth was about 30 years.
I think the point is that with modern convience and primal diet, the chance for longevity is greater not lesser. I don’t think anyone is saying let your open wound fester.
I think the point is that with modern convience and primal diet, the chance for longevity is greater not lesser. I don’t think anyone is saying let your open wound fester.
Sorry for the offtopic.
I am not a native english speaker and just started to follow the blog and the primal eating thing lately.
i thought my best bet was do ask in a new article so somebody reads it instead of an old one.
what does “finished meat” as in “grass-fed and -finished” mean?
i have some trouble to finde a discription or translation.
Samson,
Finished just refers to what the animal was fed in the last few weeks (maybe months) prior to slaughter. Many big business farms let the cattle eat grass, but then “finish” by feeding corn and other grains for the final few months in order to put on more weight quickly for profit and add fat which provides the marveling seen in grocery store meat. It is what Americans have grown to expect.
Grass fed and finished beef eats only grasses for its entire life. The meat has less fat or marveling, and can be tougher as a result. However, it also has more good omega-3 fats and less omega-6 fats than the grain finished counterparts. Cows weren’t meant to eat grains.
I hope that makes sense and is at least reasonably accurate. That is what I take it to mean.
some people justify grain-finishing by saying that wild ungulants are eating seed of grass anyway when it goes to seed.I don’t think that means we can justfy them feeding domestic seeds to cows, personally. But technically that does mean that cows in some sense eat grain naturally but t is wild grain, completely different.
Mark, cancer is not mentioned at all in the study, it seems? I often hear that hunter/gatherers didn’t get cancer because they didn’t live long enough, and that they’d have gotten it in percentages similar, or greater (since they are meat eaters and meat causes cancer) than us, but perhaps this study demolishes that idea too, since cancer is not even mentioned?
That’s not a fair comparison. Our ancestors didn’t have to deal with automobile accidents, cigarettes, BigPharma, Jerry Springer, aspartame, or Fox News.
Indeed, they didn’t have to deal with drones, gattling / automatic machine guns, and other modern implements of war. While war was not necessarily absent in the Paleolithic, wasn’t it safer in most places then than it is in very many unlucky countries that get invaded by the US, et al. now? In the end things depend on regional variation more than massive global averages would suggest.
Don’t forget that bacterial infections killed lots of people before the advent of antibiotics. I know they’re over-used today, but long ago a simple cut or scrape could potentially kill you.
Baloney. People knew proper wound care. Sure, sometimes they died form infections, but I’m here to tell you that every infection I’ve ever tried to treat naturally, from mastitis & UTIs to tooth infections & abscessed warts, I’ve succeeded. I know what to keep an eye out for, and when to give up and call in the big guns, and so far, the big guns have been able to stay put.
Excellent diet, plenty of sunshine (more than you might imagine), and megadosing vitamin C or any one of various herbal remedies … haven’t needed antibiotics in this house of 7 once since I gave them up years ago.
Speaking of natural cures… I caught athlete’s foot a little over two years ago and just couldn’t get rid of it. At first a large portion of the skin on my left foot, especially inbetween the toes, was basically dying and falling off, making it look like I was turning into a zombie. It was extremely itchy, also painful in a very annoying sort of way. I used a tube of some store bought fungicide cream, which helped quite a bit and let the skin mostly heal, but never fully cured it. For almost the next two years it would sometimes come back, making small raw patches on the top of my foot and sometimes between my toes, which would heal after a while. However, I was plagued with an itch. If I scratched, the raw patches were sure to return. So after almost two years I got another tube of cream. Once again, the cream helped a bit, but wouldn’t fully eradicate the infection. Then one day, I forget where and who, but some people were talking about peeing on wounds or something like that and someone mentioned that apparently urine cures athlete’s foot. By that point I was ready to try just about anything so I started peeing on my foot in the shower. Well, I did that for a couple weeks and it worked! I’ve been free of the itch for a few months now and I don’t think it’s coming back.
Alot of you people are not giving the ancient folks much credit-they just caught infections from any old would? Please! Herbal medicines were advanced in the paleolithic just as they are in modern HGs who have been allowed to continue their traditions. Medicine people were murdered left and right during colonization so you can not judge what people knew about healing even by what they know now that so many traditional healers were killed and their knowledge lost.
All machines are the same, including the human body – lots of “infant mortality” – design flaws (such as live birth hemorrhaging) – and finally single points of failure (old age single failure causing whole body failures).
Great article:
http://spectrum.ieee.org/biomedical/diagnostics/why-we-fall-apart
Hemorrhaging in birth is exceptionally rare when birth is natural & most importantly, mothers nurse the very moment the babe is born. The oxytocin produced is far better than the synthetic Pitocin that most doctors pump into the mother at that moment to try to mimic the natural hormone. Animals do the same, adding to the efficacy by eating the placenta!
Well, not my field so can’t help you with any “answers” but I’ll also think out loud.
1) It’s a bit of a stretch to say that any bush-baby human group is “isolated.” It’s very hard to know what contacts they’ve had in the past with Europeans or with others who have come into contact with Europeans.
2) It’s a stretch to assume that any bush-people running around in grass skirts today in any way resemble our human ancestors from 100,000 years ago, much less serve as a “model” of any sort. A couple of reasons for that: First, the span between then and now has probably caused significant evolutionary changes in bush populations. Second, many of these groups have occupied the same basic river valley, mountain range, coastline or piece of jungle for thousands of years. We simply don’t know how this relates to our ancestors who were likely more nomadic and less dominant and safe in their environment. Groups that have acclimated and learned to live in finite areas have likely reduced or adapted to external threats: They’ve developed immunity to certain diseases, they’ve killed or driven away all the tigers, they know what plants are poisonous, etc.
3) For the theory to be correct . . . i.e., humans naturally live to old age and did so 100,000 years ago . . . then we have to ask: What the hell happened? Are we saying that agriculture somehow initially reduced human life spans and that we’re now working our way out of that evolutionary hole? I’m sorry but that just seems counter-intuitive.
4) Does agriculture (grains, etc) reduce human life spans? Really? Or does agriculture create conditions for other changes that reduce our life spans? I think it’s the latter. Agriculture creates wealth and division of labor that allows people to specialize, think and do other higher level tasks . . . many of which are sedentary. They also allow significant growth in population and a more diverse gene pool.
5) Do non-agricultural groups allow that? Not to a great extent. Bands of hunters simply don’t have enough food to feed extra mouths. They can afford a few elders, but not too many. At 56, I’m in pretty good shape . . . but it’s not bloody likely that I’m going to run faster than a 16 year old or even a 36 year old. Chances are that elders get picked off first unless the tribe places some value on them. Would my clan help me walk if my ankles gave out? Would they feed me and nurse me if I fell and broke a hip? Would they risk death and injury to defend me if I was attacked by a lion? More than likely not, unless I was one of the special elders the clan needed.
In conclusion, I think the theories of our ancestors living short, brutish lives are probably correct. Agriculture has allowed us to explore technologies to sustain human life far longer than what was possible 100,000 years ago.
By our ancestors, You mean Europeans? So by your laymans perspective, everyone lived in a dangerous place. There are several flaws in your logic. The least of which presumes lion attacks as a significant threat.
You should probably read the full paper, which addresses your concerns.
I don’t know about paleolithic predators so much, but today the only predators that primarily go after young, healthy, dangerous prey are humans and lions. Most predators want to snag prey that are ill, very young, or old. I’m sure Paleolithic elderly were usually the ones targeted by predators back then.
The “!” indicates a tongue click – not easy for those of use who aren’t bushmen or Khosa, but here’s how to do it:
http://www.youtube.com/watch?v=2Mwh9z58iAU