The World Until Yesterday: What Can We Learn From Traditional Societies?

by Jared Diamond

  Seasonality and food shortage

  We have been discussing how traditional peoples cope with the danger of starvation arising from unpredictable fluctuations in food supply. Of course, there are also predictable seasonal fluctuations. Inhabitants of the temperate zones are familiar with the differences between spring, summer, fall, and winter. Even today, when food storage and long-distance food transport have evened out most seasonal variation in food availability in supermarkets, local fresh fruits and vegetables still become available on a predictable schedule. For example, near my home in Los Angeles is a farmers’ market that stocks only locally grown seasonal produce, such as asparagus in April and May, cherries and strawberries in May and June, peaches and apricots in June and July, squashes from July through January, and persimmons from October through January. In the temperate zones of North America and Eurasia, availabilities of other foods besides fresh fruits and vegetables also used to fluctuate seasonally, until modern storage and transport eliminated the fluctuations. There was an abundance of meat in the fall, when farm animals were culled and slaughtered; of milk in the spring and summer, when cows and sheep gave birth; of fish such as salmon and herring, which have predictable times of fish runs up rivers and along the coast; and of hunted migratory wild animals such as reindeer and bison at certain seasons.

  As a result, some months of the temperate-zone year were times of plenty, and other months were predictable lean times when people knew that stored food might run out and that they would at least have to tighten their belts and at worst risk starvation. For the Greenland Norse, that lean season came each year at the end of winter, when they were close to eating up the cheese, butter, and dried meat stored from the previous year, but when their cows and sheep and goats had not yet given birth and so were not yet producing milk, the herds of migratory harp seals had not yet arrived along the coast, and the resident common seals had not yet landed on beaches to give birth. It appears that the inhabitants of one of Norse Greenland’s two settlements all starved to death at the end of such a winter around 1360.

  Americans, Europeans, and other residents of the temperate zones tend to assume that tropical regions, especially near the equator, lack seasonality. While temperature is of course much less variable from month to month in the tropics than in the temperate zones, most tropical areas do have marked wet seasons and dry seasons. For instance, the town of Pomio in Papua New Guinea lies only a few hundred miles south of the equator, is very wet (260 inches of rain a year), and receives 6 inches of rain even in the driest month. However, the wettest months at Pomio (July and August) are 7 times wetter than the driest months (February and March), and that has big consequences for food availability and living conditions at Pomio. Hence people resident at low latitudes or even on the equator face predictable lean seasons, just as do traditional temperate-zone peoples. In many cases that lean season falls during the local dry season, which variously comes during the months of September and October for the !Kung of the Kalahari and for the Daribi people in the hills of Papua New Guinea, December to February for Mbuti Pygmies of the Congo’s Ituri Forest, and January for the Kaulong people of New Britain. But some other low-latitude peoples experience instead a lean season during their wettest months, which are December to March for the Ngarinyin Aborigines of Northwest Australia, and June to August for the Nuer of the Sudan.

  Table 8.2. Traditional food storage around the world

  EURASIA

  Eurasian herders Dairy products: butter, cheese, skyr, fermented milk.

  European farmers Wheat and barley, salted or dried fish, dairy products, potatoes and other tubers, pickled vegetables, beer, oil.

  Korea Kimchi: pickled fermented cabbage, turnip, cucumber. Pickled, salted, or fermented fish and shrimp.

  Ainu (Japan) Nuts, dried and frozen fish, dried venison, root starch.

  Nganasan (Siberia) Smoked, dried, or frozen reindeer meat. Rendered goose fat.

  Itenm’i (Kamchatka) Dried and fermented fish.

  AMERICAS

  Most Native American farmers Dried maize.

  Northern Plains Indians Pemmican: dried bison meat, rendered fat, and dried berries.

  Andes Freeze-dried meat and tubers and fish.

  Inuit Frozen whale meat, frozen or dried caribou meat, seal oil.

  Northwest Coast Indians Dried and smoked salmon, rendered candlefish oil, dried berries.

  Great Basin Shoshone Mesquite pod starch, pine nuts, dried meat.

  Inland Northern California Indians Acorn meal, dried salmon.

  AFRICA

  Nuer Millet, beer.

  PACIFIC

  East Polynesia Fermented taro and breadfruit. Dried bananas and starch.

  Maori (New Zealand) Bird meat, heated and sealed with fat. Tubers.

  Trobriand Islands (New Guinea) Yams.

  New Guinea lowlands Sago starch and dried fish.

  New Guinea Highlands Tubers. Sweet potatoes stored as live pigs.

  Australian Aborigines Wild grass seed cakes.

  Traditional peoples dealt with predictable seasonal food shortages in three main ways: storing food, broadening their diet, and dispersing and aggregating. The first of these methods is routine in modern society: we store food in refrigerators, deep freezers, cans, bottles, and dried packages. Many traditional societies as well set aside food surpluses accumulated during a season of food abundance (such as fall harvest time in the temperate zones), and consumed that food during a season of food scarcity (such as temperate-zone winters). Food storage was practised by sedentary societies living in markedly seasonal environments with alternating seasons of food abundance and food deficits. It was uncommon among nomadic hunter-gatherers with frequent changes of camp, because they couldn’t carry much food with them (unless they had boats or dog-drawn sleds), and the risk of pilferage by animals or other humans made it unsafe for them to leave food unguarded at one camp and to plan to return later. (However, some hunter-gatherers, such as Japan’s Ainu, Pacific Northwest Coast Indians, the Great Basin Shoshone, and some Arctic peoples, were sedentary or seasonally sedentary and stored large quantities of food.) Even among sedentary peoples, some living in small family groups stored little food because they were too few to defend a larder against raiders. Food storage was more widespread in cold temperate regions than in the hot wet tropics, where food spoils quickly. Table 8.2 gives examples.

  The main practical problem to be overcome in storing food is to prevent the food from rotting through decomposition by microorganisms. Because microbes, like all other living creatures, require mild temperatures and water, many methods of food storage involve keeping food cold (not an option in the tropics before the development of refrigerators) or else drying food. Some foods are sufficiently low in water content in their natural form that they can be stored for months or even years, as is or else after just light drying. Those foods include many nuts, cereals, some roots and tubers such as potatoes and turnips, and honey. Most of those foods are stored in containers or larders built for the purpose, but many root crops can be “stored” or banked by the simple method of leaving them in the ground for months until they are required.

  However, many other foods, such as meat and fish and juicy fruits and berries, have sufficiently high water content that they require extensive drying by means such as placing them on racks in the sun or smoking them over fires. For instance, smoked salmon, now a delicate luxury, used to be a staple prepared in large quantities by Pacific Northwest Coast Indians. Dried bison meat, combined with fat and dried berries to store as a mixture known as pemmican, was similarly a staple on the North American Great Plains. Andean Indians dried large quantities of meat, fish, potatoes, and oca by freeze-drying (alternately freezing and sun-drying).

  Still other dried foods are obtained by taking a moist raw starting-material and extracting the nutritious component without most of the original water. Familiar modern examples of such foods are olive oil made from olives, cheese made from milk, and flour made
from wheat. Traditional Mediterranean peoples, Eurasian herders, and Eurasian farmers respectively have been preparing and storing those same products for thousands of years. Rendering fat to extract it in a form with low water content was widely practised by Maori bird hunters of New Zealand, Native American bison hunters, and Arctic hunters of marine mammals. Pacific Northwest Coast Indians rendered fat from a species of smelt so oily that its English name is candlefish because when dried the fish can be burned like a candle. The staple food of the New Guinea lowlands is sago starch, obtained by extracting the starch from the pith of sago palms. Polynesians and Japan’s Ainu similarly extracted starch from roots, as did the Great Basin Shoshone Indians from mesquite pods.

  Numerous other methods of food preservation didn’t involve drying. A simple method in Arctic and northern European areas with sub-zero winter temperatures was to freeze food in the winter and bury it in the ground or in subterranean ice-filled chambers where the food would remain frozen into the next summer. I stumbled upon a vestige of that practice when, as a university student at Cambridge, England, I went on a sight-seeing drive through the East Anglian countryside with British friends with whom I shared the hobby of spelunking (exploring caves). While we were chatting with a local land-owner, he invited us to see a strange building on his land whose purpose nobody understood. It proved to be a brick dome constructed of beautifully set courses of old brick, and with a locked door that our new acquaintance opened for us. Inside, we saw in front of us a brick-lined vertical hole 10 feet in diameter, with a wooden ladder disappearing into it, and so deep that we couldn’t see a bottom.

  On the following weekend, we returned with our cave-explorers’ belaying ropes, acetylene torches, helmets, and single-piece overalls. Of course, we were hoping for a deep shaft, side galleries, and a forgotten treasure hoard. As the only American and the lightest member of our group, I was the one selected by my British friends to be the first to risk descending the rotting wooden ladder. To my disappointment, the ladder reached a dirt floor at a depth of only 30 feet, with neither side galleries, treasure, nor any other hint of function except for more beautiful courses of old brick. On my return to Cambridge that evening, I recounted our mysterious discovery over dinner. One of my table companions, an elderly engineer who spent his weekends taking walks through the countryside, exclaimed, “That’s obviously an ice-house!” He told me that such buildings used to be regular features of British estates until refrigerators began to supplant them in the late 19th century. They were excavated to a depth far below the warm surface soil layer, were filled with food and blocks of ice in the winter, and maintained food frozen into the next summer. The quantity of food that our re-discovered ice-house must have been capable of holding was huge.

  Another traditional method of food preservation is to boil food so as to kill microbes, then to seal the container while it is still hot and sterile. As recently as World War II, American city-dwellers were urged by the United States government to spare food supplies for our soldiers by patriotically planting backyard victory gardens and storing the boiled produce in air-tight vacuum jars. In the house in Boston where I grew up, my parents maintained a basement room that my mother filled with jars of tomatoes and cucumbers harvested in the autumn, and that my parents and sister and I consumed throughout the winter. My childhood was repeatedly punctuated by explosions of the antiquated pressure cooker in which my mother boiled produce before jarring it, spraying vegetable mush over our kitchen ceiling. New Zealand Maoris similarly preserved meat by cooking it and transferring it still hot into containers sealed with melted fat that kept out microbes. Without knowing about microbes, Maoris somehow discovered this method.

  The remaining class of methods preserves food without either drying or freezing or boiling, by pickling and/or fermenting with substances that prevent microbial growth. These substances include salt or vinegar added to the food, or else alcohol, vinegar, or lactic acid developing during fermentation of the food itself. Examples include beer, wine, and other alcoholic beverages; the Korean staple of kimchee served with every Korean meal, and commonly including cabbage, turnips, and cucumbers fermented in brine; the fermented mare’s milk of Asian herders; Polynesia’s fermented taro and breadfruit; and the fermented fish of Kamchatka’s Itenm’i people.

  Finally, one can achieve the purpose of storing surplus food by converting it into some non-food item that is convertible back into food during a subsequent hungry season. Farmers in our modern cash economy do this by selling their produce for money when they harvest or slaughter, banking the money, and eventually converting the money back into other foods at a supermarket. Pig husbandry by New Guinea Highlanders in effect constitutes food banking, because the staple Highland crop of sweet potatoes can be stored as is for only a few months. However, by feeding sweet potatoes to pigs and waiting several years before slaughtering the pigs, Highlanders bank the sweet potatoes, transform them into pig meat, and effectively preserve them for much longer than a few months.

  Diet broadening

  Another strategy besides food storage for coping with seasonal food scarcity is to broaden one’s diet and consume foods scorned during seasons of food plenty. In Chapter 6 I mentioned an example from Rennell Island, where people classify edible wild plants in two categories: those eaten normally, and those eaten only in desperation after a cyclone destroyed gardens. But Rennell Islanders usually obtain most of their plant food from gardens, and their classification of wild plants is not elaborate. Preferences for wild plant foods are classified much more finely among the !Kung, because traditionally they were hunter-gatherers and did not farm. They name at least 200 local wild plant species, of which they consider at least 105 edible, and which they divide along a preference hierarchy with at least six categories. Most preferred are plants that are superabundant, widely distributed, available in all months of the year, easy to collect, tasty, and considered nutritious. Number one in the hierarchy, because it meets all of these criteria, is the mongongo nut, which provides nearly half of all plant calories consumed by the !Kung and is rivaled in popularity only by meat. Lower in preference are plants that are scarce, found only locally, available only in certain months, unpleasant-tasting, hard to digest, or considered un-nutritious. When the !Kung move to a new camp, they begin by collecting mongongo nuts and their 13 other favorite plant species, until these become depleted in the vicinity. The !Kung then have to move down their food preference ladder and content themselves with less and less desirable foods. In the hot dry months of September and October, when the least food is available, the !Kung stoop to collecting fibrous tasteless roots that are ignored at other times of year, and that now are dug out and eaten without enthusiasm. About 10 species of trees exude edible resins that are rated low, considered hard to digest, and collected only incidentally as the occasion arises. At the bottom of the ladder are foods eaten only a few times a year, such as an abundant fruit thought to cause nausea and hallucinations, and meat from cows that died from eating toxic leaves. Lest you think that these food preference ladders of the !Kung are irrelevant to the lives of modern First World citizens, many Europeans adopted similar practices during the food shortages of World War II: for example, British friends told me of eating mice then, which they served up as creamed mouse.

  Within 300 miles east of the !Kung, at population densities 100 times those of the !Kung, are Gwembe Tonga farmers. When the farmers’ crops fail, the farmers’ high numbers place much greater pressure on the environment’s wild plants than do the relatively few !Kung, and so the Tonga have to reach farther down the preference ladder than do the !Kung. They then consume 21 plant species that also occur in the !Kung area but that the !Kung don’t even consider edible. One of those plants is an acacia tree whose abundant seed pods are toxic. The !Kung could collect tons of those pods each year but choose not to. However, at times of famine the Tonga do collect them and soak, boil, and leach them for a day to wash out the toxins, then eat the pods.

  My
last example of diet broadening comes from the Kaulong people of the island of New Britain, for whom garden-grown taro is the staple food and pig meat is ceremonially important. What the Kaulong call taim bilong hanggiri in Tok Pisin (i.e., “time belong hunger”) is the local dry season of October through January, when little food is available from gardens. At that time the Kaulong go into the forest to hunt, collect insects and snails and small animals, and gather wild plants about which they are understandably unenthusiastic. One of those plants is a toxic wild nut that has to be prepared by soaking it for several days to leach out its poison. Another of those second-choice plants is a wild palm tree whose trunk is roasted and eaten, and which at other times of year is scorned as pig food.

  Aggregation and dispersal

  Along with food storage and diet broadening, the remaining traditional solution to the problem created by a predictable season of food scarcity is to follow an annual cycle of population movement, aggregation, and dispersal. When food resources are few and concentrated in a few areas, people gather to live at those areas. At favorable times of year when resources are widely and uniformly distributed, people spread out over the landscape.

  A familiar European example is that farmers in the Alps spend the winter at their farmhouses in the valleys. In the spring and summer they follow the growth of new grass and the melting of snow cover up the mountain slopes, to take their flocks of cows and sheep to alpine pastures. Similar seasonal cycles of aggregation and dispersal occur among many other farming societies around the world, and among many hunter-gatherer societies including Aboriginal Australians, Inuit, Pacific Northwest Coast Indians, Great Basin Shoshone, !Kung, and African Pygmies. The times of population concentration during the lean season provide the opportunity for annual ceremonies, dances, initiations, marriage negotiations, and other occasions of group social life. The following two examples illustrate how these cycles unfold for the Shoshone and the !Kung.