The precipitating causes of most wars—primitive and civilized—are acts of violence that provoke further violence in immediate defense or subsequent retaliation. In preliterate societies, the original killing or attack that instigated a cycle of revenge may be lost in the mists of traditional enmities, but the latest violence by the other side provides ample immediate justification for further hostilities. In ethnographic accounts of the disputes that led to wars in nonstate societies, some nonviolent offenses—such as poaching, adultery, and theft—prompted an immediate violent response. But other offenses—or the same ones under other circumstances—were resolved without bloodshed or at least without causing a war.8 It was extremely rare, however, for an intergroup killing not to lead to warfare or feuding; the victim’s group invariably held the perpetrator’s group collectively responsible for the death and the latter invariably shielded the perpetrator from retribution.
It is interesting how commonly the grievances that provoked violence were economic in character. Even disputes over women often had an economic element—as we will see later. Declaring that primitive wars were fought primarily in defense or in retaliation focuses on only the most immediate or proximate causes and ignores the economic disputes underlying them. In contrast, similar economic and political disputes in civilized settings receive primary attention, whereas the “acts of war” that precipitate the fighting are treated as mere consequences.
Because archaeologists are constrained to infer human motives from circumstantial evidence, they are less likely than ethnographers and historians to become mired in hopeless efforts to extract from the statements and records of combatants the motives and causes behind wars and warfare. Perhaps the silence of archaeological evidence concerning this issue is a blessing, since it may liberate archaeologists from toiling at an impossible task. A more fruitful approach for all students of warfare may be to examine the subject using the more colorless archaeological concepts of context and association. The first of these involves isolating the general situations and circumstances in which wars are more common and warfare is more bitter. Associations are social, economic, and technological features that commonly co-occur (that is, are significantly correlated) with frequent, intense warfare. Such contexts and associations might include geographical or ecological circumstances, certain dynamics of human populations, technological change, social structure, and ideology.
POPULATION DENSITY AND PRESSURE
Since 1798, when Thomas Malthus published his famous Essay on the Principle of Population, it has been commonly assumed that violent conflicts must increase in frequency and intensity as human populations grow in size and density. The oldest and most direct argument supporting this idea is that of Malthus himself, who saw increasing population density as meaning more mouths to feed from a fixed or limited territory. In modern jargon, this dynamic process is called “population pressure on critical resources.” As this pressure increases, more people must compete for the same resources and must fight to retain or acquire them, or starve. As we saw in Chapter 7, possession of such means of production is a typical spoil of war, whether the societies involved are civilized states or foraging bands. Along with famine and disease, Malthus saw war as one of the standard consequences of overpopulation.
Modern social scientists have suggested two other reasons why increasing population density should lead to more warfare. One is a proposition in social algebra: when human numbers increase arithmetically, potential disputes increase geometrically. More conflicts are likely to arise among a thousand people than among a dozen because there are more people to argue with. Even if only a tiny proportion of all such disputes lead to bloodshed, violence should increase as density climbs. An inexact analogy might be a table of moving billiard balls: the more balls, the more potential collisions. Some biologically inclined scholars have asserted a similarity between humans and other animals, especially rats, in their reaction to “crowding stress.”9 In some experiments, rats evidenced increased levels of fighting and killing as population densities increased, even though food remained plentiful. Whatever the precise mechanism envisioned, the idea that the intensity of warfare is a function of human numbers has become widely accepted.
Cross-cultural comparisons, however, do not support this proposition. Indeed, two cross-cultural samples of societies indicate that absolutely no correlation exists between the frequency of warfare and the density of human population.10 Groups with densities of less than one person per square mile are just as likely to engage in warfare each year as groups whose densities are hundreds of times higher. The war death rates discussed in Chapter 6 likewise reveal no relationship between these measures of the intensity of warfare and the area’s population density. For example, the Piegan Indians of the Great Plains, with a density of only one person per 30 square miles, had the same casualty rate as the Grand Valley Dani of New Guinea, whose population density was nearly 10,000 times higher. The proportion of male deaths due to warfare for the Murngin Aborigines of northern Australia was about the same as that of the Dugum Dani, whose population density was 3,000 times greater. Homicide rates also bear no obvious relationship to the density of humans. To give a civilized example, the homicide rate of Britain in the thirteenth century was thirty times greater than its present one, although its population density has increased by a factor often during that period.11 In the broadest view, the frequency of warfare and violence is simply not a consequence of human density or crowding. However striking the images, human beings are neither rats packed in a cage nor irascible billiard balls jostling on a table.
But the type of population pressure that Malthus envisioned cannot be measured by simple density, since available food resources vary with ecology and technology. One person per 10 square miles may be an extraordinarily high population density in arctic tundra but an extremely rarefied one in tropical savanna. And the quantity of food produced from a given piece of ground by farmers who possess the technology to deep plow, fertilize with chemicals or manure, and irrigate exceeds that produced by dibble-stick, long-fallow, dry farming. Primitive farmers experienced land shortages and famines at far lower population densities than do their modern counterparts. Because so many factors—latitude, rainfall, soils, forest cover, biodiversity, energy input, and general technology—must be considered, making comparisons on the basis of “equivalent” population densities is extremely difficult.
Some limited comparisons can be made between societies with similar technologies and economies that live in the same general region, but since these focus on a few specific examples, they risk missing or misrepresenting the general pattern. In highland New Guinea, the percentages of deaths due to warfare of the more populous Dani and Mae Enga are significantly higher than those of the lower-density Huli. In northwestern California, the lower-density Yurok apparently had a lower annual casualty rate than did the higher-density Cahto. Among the Yanomamo peoples of South America, the higher-density Shamatari have had a significantly higher proportion of war deaths than the lower-density Namowei-teri.12 In tropical northern Australia, though, the lower-density Murngin had a higher casualty rate than the more populous Tiwi.
As was noted in Chapter 2, some of the most peaceful nonstate societies in the world had very low population densities, as in the Great Basin of North America, the Western Desert of Australia, and the dense jungles of Malaysia and central Africa. Most of these peaceable groups prevented intergroup disputes and conflicts from escalating into armed violence by fleeing from their potential adversaries. But this option can be exercised only under conditions where possessions are portable and essential resources, however scarce, are widely distributed. Merely having a low population density is not sufficient—a fact underscored by our previous point that some groups living at extremely low population densities were quite violent. From such comparisons, it appears that some relationship may exist between population pressure and the intensity of warfare, but this relationship is either very complex or very weak or bot
h. Because modern civilized states seem to go to war less frequently and to suffer proportionately fewer deaths as a result than did many primitive societies, it is at least theoretically possible that as human population density increases, the frequency of warfare and percentage of war casualties actually decline.
Admittedly, some sense of crowding may play a role in warfare, but it is usually relative—not only to the raw ecological productivity of a territory and to subsistence technology, but also to expectations and values. We have seen how commonly wars erupt when one group “crowds” another, by trespassing on its gathering plots, its fallow fields, its gardens or its women. The injured parties in such cases may fight because they feel the need to uphold their rights or because they regard such acts as representing the camel’s nose in the tent—not because their survival or health is immediately threatened. For example, many California tribes often granted outsiders the right to exploit their gathering and hunting grounds when they were properly asked or rewarded with gifts; yet they would fight any group that poached (that is, hunted, gathered, or fished without permission or reciprocation). Conversely, the trespassers in many cases of crowding were not driven to commit their offenses by the cries of their hungry families or by sexual deprivation. For example, many Inuit murders and feuds focused on women, even though wife sharing was a common practice and a convention of Inuit hospitality. Of course, some wars were indeed undertaken by groups for whom a failure to fight would have meant famine or extinction; but many wars were fought to establish control over essential resources, rather than exclusive use or absolute possession of them. In some regions, the degree of ownership or control exercised over resource locations was correlated with population density.13 Thus some higher-density groups were more likely to assert such rights and touchier about trespassing. But since conflicts over resource locations were not the only kind of war, and since groups for whom the concept of ownership did not extend beyond personal and household equipment also had frequent wars, increasing density may have changed the contexts for war but not necessarily its incidence. The only reasonable expectation to be drawn from ethnographic data is therefore that warring societies are equally common and peaceable ones equally uncommon at any level of population density.
Archaeologists, then, should be alert for signs of warfare whether the population density of their prehistoric subjects seems low or high. They should not assume (as many do) that violent conflicts could reach significant levels only when regional densities and social complexity increased to a certain threshold. In some notable archaeological cases, in fact, an increase in human density and social complexity has not been accompanied by any increase in violence.14 The Near Eastern Levant sustained a large growth in both regional or local human density and the sedentism of foraging communities between 13,000 and 11,000 years ago—a change recorded as the development of Natufian culture from the earlier Geometric Kebaran. Not only is there no evidence of an increase in warfare during this period, but there are no indications of warfare at all. In a contrary case, the last Mesolithic hunter-gatherers of central Europe (ca. 7500 years ago), whose density is estimated to have been quite low and whose way of life was rather nomadic, seem to have been quite violent, perhaps even head-hunters. Prehistoric examples such as these show that the association between human density and the intensity of warfare was as complex or weak in prehistory as in the ethnographic record.
Increasing human population densities are highly correlated with greater social and economic complexity, including such features as more complex labor-intensive technologies, labor specialization, concentration and redistribution of food surpluses by centralized leadership, and a host of other innovations that permit larger numbers to be supported from the same resource base.15 The larger, more efficient social units that result develop social and political mechanisms for resolving or suppressing violent conflicts between their members. In a reversal of social algebra, the outcome is fewer social units and fewer possible violent disputes. To return to the billiard-ball analogy, it is as though when more balls are added to the table, they merely merge into larger balls so that the rate of collision remains constant or even declines. In addition, deciding to go to war, concentrating supplies, and mobilizing men are more difficult and complicated tasks for larger societies than for smaller ones. In a small tribe, mobilization for a raid may require no more than a dozen willing recruits, each equipped with a small supply of food, and can be accomplished in a few hours. Weeks or even months may be needed to mobilize and equip the army of a chief or a king. This may be one reason why states seem to resort to war somewhat less frequently than do smaller-scale societies. The issue of whether increasing human population density is the efficient cause or merely an effect of social and economic evolution is extremely controversial among anthropologists and archaeologists, but it is clear that these variables are very closely associated. In other words, increasing population density is the mother or handmaiden of organization and invention, not the father of war.
TRADING AND RAIDING
One common assumption made by many people concerning the contexts for war and peace is that if societies are exchanging goods and marriage partners with one another, relations between them are likely to remain peaceful. This assumption underlies the often-voiced opinion that increasing trade and “cultural exchanges” between otherwise hostile nations will lessen the chances of war. This attitude reflects some social anthropological observations about what has been called the trade-raid opposition. Following the lead of the great French structuralist anthropologist Claude Lévi-Strauss, anthropologists have characterized trading and raiding as structurally opposed forms of social relations: “war is exchange gone bad, and exchange is a war averted.”16 In a brief time frame, this statement is generally true: the exchange of goods or voluntary intermarriage cannot very well take place while active hostilities are in progress. But in the longer term, assuming that intertribal exchanges of goods or intermarriage preclude warfare is a mistake.
In the modern civilized world, exchange partners commonly become periodic enemies. Historical research has found that “disputes between trading partners escalate to war more frequently than disputes between nations that do not trade much with each other.”17 A classic twentieth-century example of this phenomenon is Japan. In this century, Japan’s most important trading partner has been the United States—earlier in the century primarily as a source of essential materials for basic industry and, after World War II, also as a market for finished products. Yet it was against its largest prewar market for goods, China, and its most important source of raw material, the United States, that Japan embarked on its most disastrous war. In the same way, major shipments of grain, oil, and strategic metals poured into Nazi Germany from the Soviet Union right up to the moment the Wehrmacht invaded. Nor should we forget the close network of intermarriages and blood relationships that existed among the royal families of the belligerents in World War I. Countless examples from the primitive world demonstrate that these civilized instances are not just modern aberrations.
Ethnographers have frequently encountered tribes that intermarried and traded with one another but were also periodically at war.18 For example, the several Eskimo tribes of the Kotzebue Sound region of Alaska took part each year in a cheerful midsummer “trade fair” at Sheshalik. Besides intergroup exchange, there were intertribal feasts, dances, athletic contests, and exhibitions of magic by shamans. But the trade and these festivities did not in any way lessen the chances of war between the participants: “some of the same people who participated peacefully in the Sheshalik Fair in July could be trying to annihilate one another the following November.” Similar combinations of trade, marriage, and war between two groups within the same year also occurred in Canada and in other parts of Alaska, including relations between traditionally hostile Eskimo and Indian bands. The bellicose Tupinamba of coastal Brazil made periodic truces with their inland enemies, during which they traded coastal goods for inland commoditie
s, such that one ethnohistorian speaks of “cycles of war and commerce” between hostile groups in this region. When the Sioux came to trade at Hidatsa villages along the Upper Missouri, a truce was in force only within sight of the villages; once the nomads passed out of sight by climbing over the bluffs, they might steal horses or kill Hidatsa and were themselves subject to attack. The Mae Enga of New Guinea asserted, “We marry the people we fight.” Indeed, one very delicate battlefield task facing warriors in many New Guinea groups was how to avoid spilling the blood of in-laws fighting on the enemy side. Since intermarriage between hostile Kikuyu and Masai tribes in Kenya was not uncommon, women traded with their relatives on the other side, even during times of war. Except at the instant of trade, exchanges of marriage partners or commodities and war were by no means mutually exclusive forms of social interaction.19 Structuralist anthropologists do seem correct in seeing exchange and war as being two sides of the same coin, but the coin could be (and was) flipped frequently.
The major reason why exchange partners and enemies have often been the same people is simple propinquity. We interact most intensely with our nearest neighbors, whether those interactions are commercial, nuptial, or hostile. More intense contact also increases the chance of disputes, some of which can turn violent. However, mere proximity cannot explain why some interactions are benign, why some are violent, or why they are so often both.
War Before Civilization Page 17