Thursday, July 16, 2009

The Reality of Primitive People's Lifespan

Human lifespan is one of the topics that frequently comes up in my discussions with others about primitive nutrition and health. In our day and age, this subject has become a trendy factor in gauging the overall health of any given population or individual. If a person lives a long time -- say 100 years -- they are considered long-lived and must have lived a healthful life to reach such an impressive age. Yet, there are always anomalies to this assumption. Comedian George Burns lived to be 100 while smoking between 10-15 cigars a day. At 98, he joked, "If I'd taken my doctor's advice and quit smoking when he advised me to, I wouldn't have lived to go to his funeral."

Western cultures' obsession with lifespan has existed for a very long time. The Bible cites people living for hundreds and thousands of years in ancient times. More recently, researchers were fascinated by claims of the Hunzakats commonly reaching ages of 120 and beyond (this myth is dispelled quite well by this website). On the other end of this spectrum, many experts and laymen agree that primitive humans' lifespan was nothing to be impressed about: old age during those times was thought to be around forty years old.

Recently, I came across a study that blows all these distortions, assumptions, and obsessions out of the water. The study is a meta-analysis -- meaning it draws off of the research of many other related studies, and is titled "Longevity Among Hunter-Gatherers: A Cross-Cultural Examination." I suggest you give the full study a read, as there are many fascinating tidbits in it. The authors, Gurven and Kaplan, assembled lifespan and mortality data from around the world that included isolated hunter-gatherers (the closest living relatives to our paleolithic ancestors that we have), acculturated hunter-gatherers, isolated neolithic cultures, Western modern civilizations, and even chimpanzees for comparison. The authors focused solely on reliable demographic data from a handful of cultures. The table below sums up the results of the study well:


This data may come as a surprise to both romanticists of the ancients' supposed longevity, as well as to those that claim primitive human beings lived a life that was "nasty, brutish, and short." Here we have numbers that secure a middle ground amidst these two extremes. The authors of the study sum up their compiled information as follows:

The average modal age of adult death for hunter-gatherers is 72 with a range of 68-78 years. This range appears to be the closest functional equivelent of an "adaptive" human lifespan.

So there you have it. Convincing research suggesting that our hunter-gatherer ancestors are not at all far-removed from modern civilized human beings in terms of lifespan.

6 comments:

PaleoRD said...

Interesting study. Of course, the one thing that was not measured was the quality of life. Numerical analysis is very efficient when computing lifespans and other physical measurements. I was just reading Price's book and he has some photos of some elders who look quite good. Great post!

chlOe said...

Hahaha Baltit! From the Hunza website.. yeah that's hilarious.
No but really, nice website, quite a history lesson. If you've ever seen penn and teller's show..they're going to do an episode on organic food. Ha! I wonder if they'll mention anything the site said in it's one little paragraph on that subject.

Glad to see you put this article together.
I definitely agree with P-RD that quality of life is important - even if U.S. seems to have the highest model age, it's probably because we've got machines and medications to keep people alive-but most likely suffering in some way or another. Also..that wild versus captive chimpanzee age is absolutely amazing - I bet that has to do with stress and such. Wild animals produce so much more adrenaline and probably go through more hard times with finding food. I saw this video on Russians who tamed foxes and their colors of their coat actually started to change because of their adrenaline levels being lowered - like spotted foxes as if it were a dog's coat after about 100 years of breeding to be more docile. Just something to factor into the focus more on internal hormones and their effect on longevity.

It would only make sense that people should really put a good diet AND lifestyle (not starving themselves and working out a ton) together with a lucky lifestyle of being able to get as much food as wanted whenever.

Ryan Koch said...

PaleoRD,

I agree that quality of life is the most important factor to consider when seeking examples of optimal health. A long life doesn't necessarily mean a healthful one! I sometimes wonder why Price never mentioned the ages of the people he documented. My guess is that lifespan was not equated with health in his day and was not an important detail. Instead, Price focused on details of the primitive people's character, moral values, physical capabilities and ingratiating natures. Much better indicators of healthy people than lifespan, IMO.

Chloe,

I can always count on you to point out the humorous in the mundane. Baltit -- thanks for that. ;-)

Intreresting stuff on the captive vs. wild animals. Your thoughts on adrenaline would definitely be part of the equation when it comes to the wild animals' decreased lifespan. Other factors for early mortality would be predation, fighting between groups, injury, infection, etc.

And, yes, we humans have certainly set ourselves up for a cush life!

Thanks for the comments guys!

Dana Seilhan said...

I wonder why it's assumed that captive chimps suffer less stress? Do you think you'd be less stressed if you were raised in a manner completely counter to your evolutionary experience? Particularly if you were captured during your lifetime rather than being born in captivity?

Could it be that wild chimps' lifespans are shortened because they are hunted more often and suffer more violence? I think this is a likely answer.

I would love to see data controlled for accident rates and medical prolongation of life in wild and domesticated human populations. I'd almost be willing to bet the tribal folks would run circles around Americans and Swedes. Wild tribes suffer from lots of accidents too. There was no OSHA for the traditional Inuit.

Ryan Koch said...

Dana,

Good points regarding captive chimps. Wild chimps are certainly affected by accidents, disease, and the like, just as human beings in a primitive situation are.

Take a look at the paper I referenced in the post. The authors actually controlled for untimely deaths and included a lot of data which you might find very interesting. When it's all said and done, they concluded that primitive humans lifespan is pretty much the same as us moderns.

Anonymous said...

"Do you think you'd be less stressed if you were raised in a manner completely counter to your evolutionary experience?"

You were.

Since it says 100 percent of Chimpanzee deaths were at or above the mode, maybe its child deaths that are dragging the average down? But why doesn't that effect the primitive average? The primitive lifespan is pretty much what I expected, but does it factor in infant deaths or not? And why is there little difference between primitive and modern humans but a huge one between wild and captive chimps? Isn't it pretty much the same question of wild vs civilization. Maybe it is hunting or environmental problems.