So the lives of at least the surviving hunter-gatherers aren't nasty and brutish, even though farmers 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 by a 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 about 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 appearance 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 elite 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 elite 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 elite, dependent on oil and minerals that must often be imported 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?