To science we owe dramatic changes in our smug
self-image. Astronomy taught us that our earth isn’t the center of the
universe but merely one of billions of heavenly bodies. From biology we
learned that we weren’t specially created by God but evolved along
with millions of other species. Now archaeology is demolishing another
sacred belief: that human history over the past million years has been a
long tale of progress. In particular, recent discoveries suggest that
the adoption of agriculture, supposedly our most decisive step toward a
better life, was in many ways a catastrophe from which we have never
recovered. With agriculture came the gross social and sexual inequality,
the disease and despotism, that curse our existence.
At first, the evidence against this revisionist
interpretation will strike twentieth century Americans as irrefutable.
We’re better off in almost every respect than people of the Middle
Ages, who in turn had it easier than cavemen, who in turn were better
off than apes. Just count our advantages. We enjoy the most abundant and
varied foods, the best tools and material goods, some of the longest and
healthiest lives, in history. Most of us are safe from starvation and
predators. We get our energy from oil and machines, not from our sweat.
What neo-Luddite among us would trade his life for that of a medieval
peasant, a caveman, or an ape?
For most of our history we supported ourselves by
hunting and gathering: we hunted wild animals and foraged for wild
plants. It’s a life that philosophers have traditionally regarded as
nasty, brutish, and short. Since no food is grown and little is stored,
there is (in this view) no respite from the struggle that starts anew
each day to find wild foods and avoid starving. Our escape from this
misery was facilitated only 10,000 years ago, when in different parts of
the world people began to domesticate plants and animals. The
agricultural revolution spread until today it’s nearly universal and
few tribes of hunter-gatherers survive.
From the progressivist perspective on which I was
brought up, to ask "Why did almost all our hunter-gatherer
ancestors adopt agriculture?" is silly. Of course they adopted it
because agriculture is an efficient way to get more food for less work.
Planted crops yield far more tons per acre than roots and berries. Just
imagine a band of savages, exhausted from searching for nuts or chasing
wild animals, suddenly grazing for the first time at a fruit-laden
orchard or a pasture full of sheep. How many milliseconds do you think
it would take them to appreciate the advantages of agriculture?
The progressivist party line sometimes even goes
so far as to credit agriculture with the remarkable flowering of art
that has taken place over the past few thousand years. Since crops can
be stored, and since it takes less time to pick food from a garden than
to find it in the wild, agriculture gave us free time that
hunter-gatherers never had. Thus it was agriculture that enabled us to
build the Parthenon and compose the B-minor Mass.
While the case for the progressivist view seems
overwhelming, it’s hard to prove. How do you show that the lives of
people 10,000 years ago got better when they abandoned hunting and
gathering for farming? Until recently, archaeologists had to resort to
indirect tests, whose results (surprisingly) failed to support the
progressivist view. Here’s one example of an indirect test: Are
twentieth century hunter-gatherers really worse off than farmers?
Scattered throughout the world, several dozen groups of so-called
primitive people, like the Kalahari bushmen, continue to support
themselves that way. It turns out that these people have plenty of
leisure time, sleep a good deal, and work less hard than their farming
neighbors. For instance, the average time devoted each week to obtaining
food is only 12 to 19 hours for one group of Bushmen, 14 hours or less
for the Hadza nomads of Tanzania. One Bushman, when asked why he
hadn’t emulated neighboring tribes by adopting agriculture, replied,
"Why should we, when there are so many mongongo nuts in the
world?"
While farmers concentrate on high-carbohydrate
crops like rice and potatoes, the mix of wild plants and animals in the
diets of surviving hunter-gatherers provides more protein and a bettter
balance of other nutrients. In one study, the Bushmen’s average daily
food intake (during a month when food was plentiful) was 2,140 calories
and 93 grams of protein, considerably greater than the recommended daily
allowance for people of their size. It’s almost inconceivable that
Bushmen, who eat 75 or so wild plants, could die of starvation the way
hundreds of thousands of Irish farmers and their families did during the
potato famine of the 1840s.
So the lives of at least the surviving
hunter-gatherers aren’t nasty and brutish, even though farmes have
pushed them into some of the world’s worst real estate. But modern
hunter-gatherer societies that have rubbed shoulders with farming
societies for thousands of years don’t tell us about conditions before
the agricultural revolution. The progressivist view is really making a
claim about the distant past: that the lives of primitive people
improved when they switched from gathering to farming. Archaeologists
can date that switch by distinguishing remains of wild plants and
animals from those of domesticated ones in prehistoric garbage dumps.
How can one deduce the health of the prehistoric
garbage makers, and thereby directly test the progressivist view? That
question has become answerable only in recent years, in part through the
newly emerging techniques of paleopathology, the study of signs of
disease in the remains of ancient peoples.
In some lucky situations, the paleopathologist has
almost as much material to study as a pathologist today. For example,
archaeologists in the Chilean deserts found well preserved mummies whose
medical conditions at time of death could be determined by autopsy
(Discover, October). And feces of long-dead Indians who lived in dry
caves in Nevada remain sufficiently well preserved to be examined for
hookworm and other parasites.
Usually the only human remains available for study
are skeletons, but they permit a surprising number of deductions. To
begin with, a skeleton reveals its owner’s sex, weight, and
approximate age. In the few cases where there are many skeletons, one
can construct mortality tables like the ones life insurance companies
use to calculate expected life span and risk of death at any given age.
Paleopathologists can also calculate growth rates by measuring bones of
people of different ages, examine teeth for enamel defects (signs of
childhood malnutrition), and recognize scars left on bones by anemia,
tuberculosis, leprosy, and other diseases.
One straight forward example of what
paleopathologists have learned from skeletons concerns historical
changes in height. Skeletons from Greece and Turkey show that the
average height of hunger-gatherers toward the end of the ice ages was a
generous 5’ 9" for men, 5’ 5" for women. With the adoption
of agriculture, height crashed, and by 3000 B. C. had reached a low of
only 5’ 3" for men, 5’ for women. By classical times heights
were very slowly on the rise again, but modern Greeks and Turks have
still not regained the average height of their distant ancestors.
Another example of paleopathology at work is the
study of Indian skeletons from burial mounds in the Illinois and Ohio
river valleys. At Dickson Mounds, located near the confluence of the
Spoon and Illinois rivers, archaeologists have excavated some 800
skeletons that paint a picture of the health changes that occurred when
a hunter-gatherer culture gave way to intensive maize farming around A.
D. 1150. Studies by George Armelagos and his colleagues then at the
University of Massachusetts show these early farmers paid a price for
their new-found livelihood. Compared to the hunter-gatherers who
preceded them, the farmers had a nearly 50 per cent increase in enamel
defects indicative of malnutrition, a fourfold increase in
iron-deficiency anemia (evidenced bya bone condition called porotic
hyperostosis), a theefold rise in bone lesions reflecting infectious
disease in general, and an increase in degenerative conditions of the
spine, probably reflecting a lot of hard physical labor. "Life
expectancy at birth in the pre-agricultural community was bout
twenty-six years," says Armelagos, "but in the
post-agricultural community it was nineteen years. So these episodes of
nutritional stress and infectious disease were seriously affecting their
ability to survive."
The evidence suggests that the Indians at Dickson
Mounds, like many other primitive peoples, took up farming not by choice
but from necessity in order to feed their constantly growing numbers.
"I don’t think most hunger-gatherers farmed until they had to,
and when they switched to farming they traded quality for
quantity," says Mark Cohen of the State University of New York at
Plattsburgh, co-editor with Armelagos, of one of the seminal books in
the field, Paleopathology at the Origins of Agriculture.
"When I first started making that argument ten years ago, not many
people agreed with me. Now it’s become a respectable, albeit
controversial, side of the debate."
There are at least three sets of reasons to
explain the findings that agriculture was bad for health. First,
hunter-gatherers enjoyed a varied diet, while early farmers obtained
most of their food from one or a few starchy crops. The farmers gained
cheap calories at the cost of poor nutrition. (today just three
high-carbohydrate plants–wheat, rice, and corn–provide the bulk of
the calories consumed by the human species, yet each one is deficient in
certain vitamins or amino acids essential to life.) Second, because of
dependence on a limited number of crops, farmers ran the risk of
starvation if one crop failed. Finally, the mere fact that agriculture
encouraged people to clump together in crowded societies, many of which
then carried on trade with other crowded societies, led to the spread of
parasites and infectious disease. (Some archaeologists think it was the
crowding, rather than agriculture, that promoted disease, but this is a
chicken-and-egg argument, because crowding encourages agriculture and
vice versa.) Epidemics couldn’t take hold when populations were
scattered in small bands that constantly shifted camp. Tuberculosis and
diarrheal disease had to await the rise of farming, measles and bubonic
plague the appearnce of large cities.
Besides malnutrition, starvation, and epidemic
diseases, farming helped bring another curse upon humanity: deep class
divisions. Hunter-gatherers have little or no stored food, and no
concentrated food sources, like an orchard or a herd of cows: they live
off the wild plants and animals they obtain each day. Therefore, there
can be no kings, no class of social parasites who grow fat on food
seized from others. Only in a farming population could a healthy,
non-producing élite set itself above the disease-ridden masses.
Skeletons from Greek tombs at Mycenae c. 1500 B. C. suggest that royals
enjoyed a better diet than commoners, since the royal skeletons were two
or three inches taller and had better teeth (on the average, one instead
of six cavities or missing teeth). Among Chilean mummies from c. A. D.
1000, the élite were distinguished not only by ornaments and gold hair
clips but also by a fourfold lower rate of bone lesions caused by
disease.
Similar contrasts in nutrition and health persist
on a global scale today. To people in rich countries like the U. S., it
sounds ridiculous to extol the virtues of hunting and gathering. But
Americans are an élite, dependent on oil and minerals that must often
be iimproted from countries with poorer health and nutrition. If one
could choose between being a peasant farmer in Ethiopia or a bushman
gatherer in the Kalahari, which do you think would be the better choice?
Farming may have encouraged inequality between the
sexes, as well. Freed from the need to transport their babies during a
nomadic existence, and under pressure to produce more hands to till the
fields, farming women tended to have more frequent pregnancies than
their hunter-gatherer counterparts–with consequent drains on their
health. Among the Chilean mummies for example, more women than men had
bone lesions from infectious disease.
Women in agricultural societies were sometimes
made beasts of burden. In New Guinea farming communities today I often
see women staggering under loads of vegetables and firewood while the
men walk empty-handed. Once while on a field trip there studying birds,
I offered to pay some villagers to carry supplies from an airstrip to my
mountain camp. The heaviest item was a 110-pound bag of rice, which I
lashed to a pole and assigned to a team of four men to shoulder
together. When I eventually caught up with the villagers, the men were
carrying light loads, while one small woman weighing less than the bag
of rice was bent under it, supporting its weight by a cord across her
temples.
As for the claim that agriculture encouraged the
flowering of art by providing us with leisure time, modern
hunter-gatherers have at least as much free time as do farmers. The
whole emphasis on leisure time as a critical factor seems to me
misguided. Gorillas have had ample free time to build their own
Parthenon, had they wanted to. While post-agricultural technological
advances did make new art forms possible and preservation of art easier,
great paintings and sculptures were already being produced by
hunter-gatherers 15,000 years ago, and were still being produced as
recently as the last century by such hunter-gatherers as some Eskimos
and the Indians of the Pacific Northwest.
Thus with the advent of agriculture and élite
became better off, but most people became worse off. Instead of
swallowing the progressivist party line that we chose agriculture
because it was good for us, we must ask how we got trapped by it despite
its pitfalls.
One answer boils down to the adage "Might
makes right." Farming could support many more people than hunting,
albeit with a poorer quality of life. (Population densities of
hunter-gatherers are rarely over on eperson per ten square miles, while
farmers average 100 times that.) Partly, this is because a field planted
entirely in edible crops lets one feed far more mouths than a forest
with scattered edible plants. Partly, too, it’s because nomadic
hunter-gatherers have to keep their children spaced at four-year
intervals by infanticide and other means, since a mother must carry her
toddler until it’s old enough to keep up with the adults. Because farm
women don’t have that burden, they can and often do bear a child every
two years.
As population densities of hunter-gatherers slowly
rose at the end of the ice ages, bands had to choose between feeding
more mouths by taking the first steps toward agriculture, or else
finding ways to limit growth. Some bands chose the former solution,
unable to anticipate the evils of farming, and seduced by the transient
abundance they enjoyed until population growth caught up with increased
food production. Such bands outbred and then drove off or killed the
bands that chose to remain hunter-gatherers, because a hundred
malnourished farmers can still outfight one healthy hunter. It’s not
that hunter-gatherers abandonded their life style, but that those
sensible enough not to abandon it were forced out of all areas except
the ones farmers didn’t want.
At this point it’s instructive to recall the
common complaint that archaeology is a luxury, concerned with the remote
past, and offering no lessons for the present. Archaeologists studying
the rise of farming have reconstructed a crucial stage at which we made
the worst mistake in human history. Forced to choose between limiting
population or trying to increase food production, we chose the latter
and ended up with starvation, warfare, and tyranny.
Hunter-gatherers practiced the most successful and
logest-lasting life style in human history. In contrast, we’re still
struggling with the mess into which agriculture has tumbled us, and
it’s unclear whether we can solve it. Suppose that an archaeologist
who had visited from outer space were trying to explain human history to
his fellow spacelings. He might illustrate the results of his digs by a
24-hour clock on which one hour represents 100,000 years of real past
time. If the history of the human race began at midnight, then we would
now be almost at the end of our first day. We lived as hunter-gatherers
for nearly the whole of that day, from midnight through dawn, noon, and
sunset. Finally, at 11:54 p. m. we adopted agriculture. As our second
midnight approaches, will the plight of famine-stricken peasants
gradually spread to engulf us all? Or will we somehow achieve those
seductive blessings that we imagine behind agriculture’s glittering façade,
and that have so far eluded us?
Jared
Diamond
University of
California at Los Angeles Medical School