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

by Jared Diamond

  Furthermore, food shortage takes the form not only of starvation in the sense of insufficient calories, but also shortages of specific vitamins (causing diseases such as beriberi, pellagra, pernicious anemia, rickets, and scurvy), specific minerals (causing endemic goiter and iron-deficiency anemia), and protein (causing kwashiorkor). Those specific deficiency diseases are more frequent among farmers than among hunter-gatherers, whose diets tend to be more varied than those of farmers. Like calorie starvation, specific deficiency diseases are likely to contribute to someone being recorded as dying of an accident, violence, or infectious disease before the person dies of the deficiency disease alone.

  Starvation is a risk that affluent First World citizens don’t even think about, because our access to food remains the same, day after day, from season to season, and year after year. Of course, we have some particular foods that are seasonal and available for just a few weeks a year, such as freshly harvested local cherries, but the total available amount of food is essentially constant. For small-scale societies, however, there are unpredictably good or bad days, some season each year when food is predictably short and to which people look forward with foreboding, and unpredictably good or bad years. As a result, food is a major and almost constant subject of conversation. I was initially surprised that my Fore friends spent so much time talking about sweet potatoes, even after they had just eaten to satiation. For the Siriono Indians of Bolivia, the overwhelming preoccupation is with food, such that two of the commonest Siriono expressions are “My stomach is empty” and “Give me some food.” The significance of sex and food is reversed between the Siriono and us Westerners: the Sirionos’ strongest anxieties are about food, they have sex virtually whenever they want, and sex compensates for food hunger, while our strongest anxieties are about sex, we have food virtually whenever we want, and eating compensates for sexual frustration.

  Unlike us, many traditional societies, especially ones in arid or Arctic environments, face frequent predictable and unpredictable food shortages, and their risk of famine is far higher than ours. The reasons for this difference are clear. Many traditional societies have few or no stored food surpluses on which to fall back, either because they can’t produce surpluses to store, or because a hot wet climate would cause food to spoil quickly, or because their lifestyle is nomadic. Those groups that actually could store surplus food risk losing it to raiders. Traditional societies are threatened by local food failures because they can integrate food resources only over a small area, whereas we First World citizens ship food over our whole country and import it from the most distant countries. Without our motorized vehicles, roads, railroads, and ships, traditional societies can’t transport food long distances and can acquire it only from near neighbors. Traditional societies lack our state governments that organize food storage, transport, and exchange over large areas. Nevertheless, we shall see that traditional societies have many other ways of coping with the risk of famine.

  Unpredictable food shortages

  The shortest time scale and smallest spatial scale of variation in tribal food supply involve day-to-day variation in individual hunting success. Plants don’t move around and can be gathered more or less predictably from one day to the next, but animals do move, so that any individual hunter risks bagging no animal on any given day. The solution to that uncertainty adopted almost universally by hunter-gatherers is to live in bands including several hunters who pool their catch to average out the large day-to-day fluctuations in catch for each individual hunter. Richard Lee described that solution from his own experience with the !Kung of Africa’s Kalahari Desert, but he was also generalizing for hunter-gatherers of all continents and all environments when he wrote: “Food is never consumed alone by a family; it is always (actually or potentially) shared out with members of a living group or band of up to 30 (or more) members. Even though only a fraction of the able-bodied foragers go out each day, the day’s returns of meat and gathered foods are divided in such a way that every member of the camp receives an equitable share. The hunting band or camp is a unit of sharing.” His principle of pooling and averaging among hunter-gatherers also applies to many small-scale herding and farming societies, such as the Sudan’s Nuer people studied by E. E. Evans-Pritchard, who share meat, milk, fish, grain, and beer: “Although a household owns its own food, does its own cooking, and provides independently for the needs of its members, men, and much less, women and children, eat in one another’s homes to such an extent that, looked at from outside, the whole community is seen to be partaking of a joint supply. Rules of hospitality and conventions about the division of meat and fish lead to a far wider sharing of food than a bare statement of the principles of ownership would suggest.”

  The next longer and larger scale of variation in food supply involves unpredictable variation in food availability affecting a whole local group. A spell of cold wet weather lasting a few days makes it unrewarding and dangerous for Ache Indians to go out hunting, and leaves them not only hungry but also at risk of cold exposure and respiratory infections. Ripening of the local crop of plantains and peach palm fruits, which are staple plant foods for Yanomamo Indians, occurs unpredictably: there is either none to eat, or else a local superabundance. The millet crop of the Nuer may be ruined by drought, elephants, heavy rain, locusts, or weaverbirds. Severe droughts that cause famine afflict !Kung hunter-gatherers unpredictably in about one out of four years, and are uncommon but feared among Trobriand Island farmers. Frosts kill the staple sweet potato crop in about 1 out of 10 years among New Guinea Highland farmers at high elevation. Destructive cyclones strike the Solomon Islands at irregular intervals of one to several decades.

  Small-scale societies attempt to cope with these unpredictable local food failures in several ways that include shifting camp, storing food in their own bodies, agreements between different local groups, and scattering land for food production. The simplest solution for nomadic hunter-gatherers not tied to fixed gardens, and faced with local food scarcity, is to move to another location where food availability is at the moment higher. As for fattening up whenever possible, if problems of food rotting or of enemy raiders prevent you from storing food in a larder or container, you can at least store it as your own body fat, which won’t rot and can’t be stolen. In Chapter 11 I’ll give examples of small-scale societies that gorge, when food is abundant, to a degree unbelievable to Westerners, except for those few of us who have competed in hot-dog-eating contests. People thereby fatten themselves and become better able to survive subsequent times of food scarcity.

  While gorging may help you carry yourself through a few weeks of food scarcity, it won’t protect you against a year of starvation. One long-term solution is to make reciprocal agreements with neighboring groups about sharing food when one group’s area has enough food and another group’s area is suffering from a food shortage. Local food availability fluctuates with time in any area. But two areas located a sufficient distance apart are likely to have fluctuations in food availability that are out of phase. That opens the door for your group to reach a mutually advantageous agreement with another group, such that they allow you onto their land or send you food when they have enough food but you don’t, and your group returns the favor when it’s the other group that’s short of food.

  For example, in the area of the Kalahari Desert occupied by the !Kung San, rainfall in a given month varies by up to a factor of 10 between different sites. The result, in Richard Lee’s words, is that “the desert may be blooming in one area and a few hours’ walk away, the land may still be parched.” As one example, Lee compared monthly rainfall at five sites in the Ghanzi district for 12 months from July 1966 to June 1967. The total rainfall for the year varied by less than a factor of 2 between sites, but rainfall in a given month varied among sites from no rainfall at all to 10 inches. The site of Cume had the highest annual rainfall but was nevertheless the driest of the five sites in May 1967 and the second driest in November 1966 and February 1967.
Conversely, Kalkfontein had the lowest annual rainfall, but it was the second-wettest site in March 1967 and again in May 1967. Hence for any site, a group confined to that site would be certain to experience droughts and food shortages at certain times, but could usually find some other group whose site was wet and flourishing—provided that the two groups had agreed to help each other in times of need. In fact, such generalized reciprocity is essential to the !Kung’s ability to survive in their locally unpredictable desert environment.

  Reciprocity (punctuated occasionally by hostility) is widespread among traditional societies. Trobriand Island villages distribute food between villages to even out local food shortages. Among the Iñupiat of northern Alaska, individual families in times of local famine moved to live with relatives or partners in another district. The most important fruits consumed by South America’s Yanomamo Indians come from groves of peach palm trees and plantain trees, both of which (especially the former) produce harvests more abundant than a local group can consume by itself. The fruits spoil after ripening and cannot be stored, so they have to be eaten while ripe. When a local group finds itself with a surplus, it invites neighbors to come for a feast, in the expectation that those neighbors will reciprocate when they in turn produce a food surplus.

  Scatter your land

  The other common long-term solution to the unpredictable risk of a local food shortage is to scatter your land-holdings. I encountered this phenomenon in New Guinea when, while out bird-watching one day, I stumbled across a New Guinea friend’s garden clearing in the middle of forest a mile northeast of his village, and several miles from his other gardens scattered to the south and west of his village. What on earth did he have in mind, I asked myself, when he chose that isolated location for his new garden? It seemed so inefficient to commit himself to a waste of travel time, and the garden’s remoteness made it hard to protect from marauding pigs and thieves. But New Guineans are smart and experienced gardeners. If you see them doing something that you initially don’t understand, there usually turns out to be a reason. What was his motive?

  Other Western scholars and development experts have been equally puzzled by other cases of field scattering elsewhere in the world. The example most often discussed involves medieval English peasants, who tilled dozens of tiny scattered plots. To modern economic historians, that was “obviously” a bad idea because of the resulting wasted travel and transport time and inevitable unplowed strips between plots. A similar modern case of field scattering by Andean peasant farmers near Lake Titicaca, studied by Carol Goland, provoked development experts to write in exasperation, “The peasants’ cumulative agricultural efficiency is so appalling…that our amazement is how these people even survive at all…. Because inheritance and marriage traditions continually fragment and scatter a peasant’s fields over numerous villages, the average peasant spends three-quarters of his day walking between fields that sometimes measure less than a few square feet.” The experts proposed land-swapping among farmers in order to consolidate their holdings.

  But Goland’s quantitative study in the Peruvian Andes showed that there really is method to such apparent madness. In the Cuyo Cuyo district, the peasant farmers whom Goland studied grow potatoes and other crops in scattered fields: on the average 17 fields, up to a maximum of 26 fields, per farmer, each field with an average size of only 50 by 50 feet. Because the farmers occasionally rent or buy fields, it would be perfectly possible for them in that way to consolidate their holdings, but they don’t. Why not?

  A clue noticed by Goland was the variation in crop yield from field to field, and from year to year. Only a small part of that variation is predictable from the environmental factors of field elevation, slope, and exposure, and from work-related factors under the peasants’ control (such as their effort in fertilizing and weeding the field, seed density, and planting date). Most of that variation is instead unpredictable, uncontrollable, and somehow related to the local amount and timing of rain for that year, frosts, crop diseases, pests, and theft by people. In any given year there are big differences between yields of different fields, but a peasant can’t predict which particular field is going to produce well in any particular year.

  What a Cuyo Cuyo peasant family has to do at all costs is to avoid ending up at the end of any year with a low harvest that would leave the family starving. In the Cuyo Cuyo area, farmers can’t produce enough storable food surpluses in a good year to carry them through a subsequent bad year. Hence it is not the peasant’s goal to produce the highest possible time-averaged crop yield, averaged over many years. If your time-averaged yield is marvelously high as a result of the combination of nine great years and one year of crop failure, you will still starve to death in that one year of crop failure before you can look back to congratulate yourself on your great time-averaged yield. Instead, the peasant’s aim is to make sure to produce a yield above the starvation level in every single year, even though the time-averaged yield may not be highest. That’s why field scattering may make sense. If you have just one big field, no matter how good it is on the average, you will starve when the inevitable occasional year arrives in which your one field has a low yield. But if you have many different fields, varying independently of each other, then in any given year some of your fields will produce well even when your other fields are producing poorly.

  To test this hypothesis, Goland measured the yields of all the fields of 20 families—488 individual fields in all—in each of two successive years. She then calculated what each family’s total crop yield, pooled over all their fields, would have been if, while still cultivating the same total field area, they had concentrated all their fields at one of their actual locations, or if instead they had scattered their fields at 2, 3, 4, etc. up to 14 different ones of the actual locations. It turned out that, the more numerous were the scattered locations, the lower was the calculated time-averaged yield, but also the lower was the risk of ever dropping below the starvation yield level. For instance, a family that Goland labeled family Q, which consisted of a middle-aged husband and wife and a 15-year-old daughter, was estimated to need 1.35 tons of potatoes per acre of land per year in order to avoid starvation. For that family, planting at just a single location would have meant a high risk (37%!) of starving in any given year. It would have been no consolation to family Q, as they sat starving to death in a bad year such as arrives about once in every three years, to reflect that that choice of a single location gave them the highest time-averaged yield of 3.4 tons per acre, more than double the starvation level. Combinations of up to six locations also exposed them to the risk of occasional starvation. Only if they planted seven or more locations did their risk of starvation drop to zero. Granted, their average yield for seven or more locations had dropped to 1.9 tons per acre, but it never dropped below 1.5 tons per acre, so they never starved.

  On the average, Goland’s 20 families actually planted two or three more fields than the number of fields that she calculated that they had to plant in order to avoid starvation. Of course, that field scattering did force them to burn more calories while walking and transporting things between their scattered fields. However, Goland calculated that the extra calories thereby burned up were only 7% of their crop calorie yields, an acceptable price to pay for avoiding starvation.

  In brief, through long experience, and without using statistics or mathematical analyses, Goland’s Andean peasants had figured out how to scatter their land just enough to buffer them against the risk of starvation from unpredictable local variation in food yields. The peasants’ strategy fits the precept “Don’t put all your eggs in one basket.” Similar considerations probably also explain field scattering by medieval English peasants. The same considerations may explain why the Lake Titicaca peasants so harshly criticized by exasperated agricultural development researchers for appalling inefficiency were actually smart, and why it was actually the researchers’ land-swapping advice that was appalling. As for my New Guinea friend whose isolated gar
den several miles from his other gardens initially puzzled me, his people mentioned five reasons for scattering their gardens: to reduce the risks of all their gardens simultaneously being devastated by a wind-storm, crop disease, pigs, or rats, and to obtain a wider variety of crops by planting at three different elevations in different climatic zones. Those New Guinea farmers are similar to Goland’s Andean farmers, except for planting fewer but larger gardens (on the average, 7 gardens with a range from 5 to 11 for the New Guineans, instead of 17 fields with a range from 9 to 26 for the Andean farmers).

  Far too many American investors forget the difference, recognized by peasant farmers around the world, between maximizing time-averaged yields and making sure that yields never drop below some critical level. If you are investing money that you are sure you won’t need soon, just to spend in the distant future or for luxuries, it’s appropriate to aim to maximize your time-averaged yield, regardless of whether yields become zero or negative in occasional bad years. But if you depend on your investment earnings to pay current expenses, your strategy should be that of the peasants: make sure that your annual earnings always remain above the level necessary for your maintenance, even if that means having to settle for a lower time-averaged yield. As I write these lines, some of the smartest investors in the United States are suffering the consequences of ignoring that difference. Harvard University has the largest endowment, and has had the highest time-averaged endowment earnings rate, of any American university. Its endowment managers became legendary for their skill, success, and willingness to explore profitable types of investments previously shunned by conservative university investment managers. The salary of a Harvard manager was linked to the long-term average growth rate of the portion of Harvard’s portfolio for which that manager was responsible. Unfortunately, Harvard’s investment income is not reserved for luxuries or a rainy day but contributes about half of the operating budget of Harvard College. During the worldwide financial meltdown of 2008–2009, Harvard’s endowment principal and income crashed, as did so many other investments aimed at maximizing long-term yields, so Harvard was forced to impose a hiring freeze and to postpone indefinitely its billion-dollar plan for a new science campus. In retrospect, Harvard’s managers should have followed the strategy practised by so many peasant farmers (Plate 45).