However, this “hydraulic theory” of state formation is subject to the same objections leveled against social contract theories in general. More specifically, it addresses only the final stage in the evolution of complex societies. It says nothing about what drove the progression from bands to tribes to chiefdoms during all the millennia before the prospect of large-scale irrigation loomed up on the horizon. When historical or archaeological dates are examined in detail, they fail to support the view of irrigation as the driving force for state formation. In Mesopotamia, North China, Mexico, and Madagascar, small-scale irrigation systems already existed before the rise of states. Construction of large-scale irrigation systems did not accompany the emergence of states but came only significantly later in each of those areas. In most of the states formed over the Maya area of Mesoamerica and the Andes, irrigation systems always remained small-scale ones that local communities could build and maintain themselves. Thus, even in those areas where complex systems of hydraulic management did emerge, they were a secondary consequence of states that must have formed for other reasons.
What seems to me to point to a fundamentally correct view of state formation is an undoubted fact of much wider validity than the correlation between irrigation and the formation of some states—namely, that the size of the regional population is the strongest single predictor of societal complexity. As we have seen, bands number a few dozen individuals, tribes a few hundred, chiefdoms a few thousand to a few tens of thousands, and states generally over about 50,000. In addition to that coarse correlation between regional population size and type of society (band, tribe, and so on), there is a finer trend, within each of those categories, between population and societal complexity: for instance, that chiefdoms with large populations prove to be the most centralized, stratified, and complex ones.
These correlations suggest strongly that regional population size or population density or population pressure has something to do with the formation of complex societies. But the correlations do not tell us precisely how population variables function in a chain of cause and effect whose outcome is a complex society. To trace out that chain, let us now remind ourselves how large dense populations themselves arise. Then we can examine why a large but simple society could not maintain itself. With that as background, we shall finally return to the question of how a simpler society actually becomes more complex as the regional population increases.
WE HAVE SEEN that large or dense populations arise only under conditions of food production, or at least under exceptionally productive conditions for hunting-gathering. Some productive hunter-gatherer societies reached the organizational level of chiefdoms, but none reached the level of states: all states nourish their citizens by food production. These considerations, along with the just mentioned correlation between regional population size and societal complexity, have led to a protracted chicken-or-egg debate about the causal relations between food production, population variables, and societal complexity. Is it intensive food production that is the cause, triggering population growth and somehow leading to a complex society? Or are large populations and complex societies instead the cause, somehow leading to intensification of food production?
Posing the question in that either-or form misses the point. Intensified food production and societal complexity stimulate each other, by autocatalysis. That is, population growth leads to societal complexity, by mechanisms that we shall discuss, while societal complexity in turn leads to intensified food production and thereby to population growth. Complex centralized societies are uniquely capable of organizing public works (including irrigation systems), long-distance trade (including the importation of metals to make better agricultural tools), and activities of different groups of economic specialists (such as feeding herders with farmers’ cereal, and transferring the herders’ livestock to farmers for use as plow animals). All of these capabilities of centralized societies have fostered intensified food production and hence population growth throughout history.
In addition, food production contributes in at least three ways to specific features of complex societies. First, it involves seasonally pulsed inputs of labor. When the harvest has been stored, the farmers’ labor becomes available for a centralized political authority to harness—in order to build public works advertising state power (such as the Egyptian pyramids), or to build public works that could feed more mouths (such as Polynesian Hawaii’s irrigation systems or fishponds), or to undertake wars of conquest to form larger political entities.
Second, food production may be organized so as to generate stored food surpluses, which permit economic specialization and social stratification. The surpluses can be used to feed all tiers of a complex society: the chiefs, bureaucrats, and other members of the elite; the scribes, craftspeople, and other non-food-producing specialists; and the farmers themselves, during times that they are drafted to construct public works.
Finally, food production permits or requires people to adopt sedentary living, which is a prerequisite for accumulating substantial possessions, developing elaborate technology and crafts, and constructing public works. The importance of fixed residence to a complex society explains why missionaries and governments, whenever they make first contact with previously uncontacted nomadic tribes or bands in New Guinea or the Amazon, universally have two immediate goals. One goal, of course, is the obvious one of “pacifying” the nomads: that is, dissuading them from killing missionaries, bureaucrats, or each other. The other goal is to induce the nomads to settle in villages, so that the missionaries and bureaucrats can find the nomads, bring them services such as medical care and schools, and proselytize and control them.
THUS, FOOD PRODUCTION, which increases population size, also acts in many ways to make features of complex societies possible. But that doesn’t prove that food production and large populations make complex societies inevitable. How can we account for the empirical observation that band or tribal organization just does not work for societies of hundreds of thousands of people, and that all existing large societies have complex centralized organization? We can cite at least four obvious reasons.
One reason is the problem of conflict between unrelated strangers. That problem grows astronomically as the number of people making up the society increases. Relationships within a band of 20 people involve only 190 two-person interactions (20 people times 19 divided by 2), but a band of 2,000 would have 1,999,000 dyads. Each of those dyads represents a potential time bomb that could explode in a murderous argument. Each murder in band and tribal societies usually leads to an attempted revenge killing, starting one more unending cycle of murder and countermurder that destabilizes the society.
In a band, where everyone is closely related to everyone else, people related simultaneously to both quarreling parties step in to mediate quarrels. In a tribe, where many people are still close relatives and everyone at least knows everybody else by name, mutual relatives and mutual friends mediate the quarrel. But once the threshold of “several hundred,” below which everyone can know everyone else, has been crossed, increasing numbers of dyads become pairs of unrelated strangers. When strangers fight, few people present will be friends or relatives of both combatants, with self-interest in stopping the fight. Instead, many onlookers will be friends or relatives of only one combatant and will side with that person, escalating the two-person fight into a general brawl. Hence a large society that continues to leave conflict resolution to all of its members is guaranteed to blow up. That factor alone would explain why societies of thousands can exist only if they develop centralized authority to monopolize force and resolve conflicts.
A second reason is the growing impossibility of communal decision making with increasing population size. Decision making by the entire adult population is still possible in New Guinea villages small enough that news and information quickly spread to everyone, that everyone can hear everyone else in a meeting of the whole village, and that everyone who wants to speak at the meeting has the
opportunity to do so. But all those prerequisites for communal decision making become unattainable in much larger communities. Even now, in these days of microphones and loudspeakers, we all know that a group meeting is no way to resolve issues for a group of thousands of people. Hence a large society must be structured and centralized if it is to reach decisions effectively.
A third reason involves economic considerations. Any society requires means to transfer goods between its members. One individual may happen to acquire more of some essential commodity on one day and less on another. Because individuals have different talents, one individual consistently tends to wind up with an excess of some essentials and a deficit of others. In small societies with few pairs of members, the resulting necessary transfers of goods can be arranged directly between pairs of individuals or families, by reciprocal exchanges. But the same mathematics that makes direct pairwise conflict resolution inefficient in large societies makes direct pairwise economic transfers also inefficient. Large societies can function economically only if they have a redistributive economy in addition to a reciprocal economy. Goods in excess of an individual’s needs must be transferred from the individual to a centralized authority, which then redistributes the goods to individuals with deficits.
A final consideration mandating complex organization for large societies has to do with population densities. Large societies of food producers have not only more members but also higher population densities than do small bands of hunter-gatherers. Each band of a few dozen hunters occupies a large territory, within which they can acquire most of the resources essential to them. They can obtain their remaining necessities by trading with neighboring bands during intervals between band warfare. As population density increases, the territory of that band-sized population of a few dozen would shrink to a small area, with more and more of life’s necessities having to be obtained outside the area. For instance, one couldn’t just divide Holland’s 16,000 square miles and 16,000,000 people into 800,000 individual territories, each encompassing 13 acres and serving as home to an autonomous band of 20 people who remained self-sufficient confined within their 13 acres, occasionally taking advantage of a temporary truce to come to the borders of their tiny territory in order to exchange some trade items and brides with the next band. Such spatial realities require that densely populated regions support large and complexly organized societies.
Considerations of conflict resolution, decision making, economics, and space thus converge in requiring large societies to be centralized. But centralization of power inevitably opens the door—for those who hold the power, are privy to information, make the decisions, and redistribute the goods—to exploit the resulting opportunities to reward themselves and their relatives. To anyone familiar with any modern grouping of people, that’s obvious. As early societies developed, those acquiring centralized power gradually established themselves as an elite, perhaps originating as one of several formerly equal-ranked village clans that became “more equal” than the others.
THOSE ARE THE reasons why large societies cannot function with band organization and instead are complex kleptocracies. But we are still left with the question of how small, simple societies actually evolve or amalgamate into large, complex ones. Amalgamation, centralized conflict resolution, decision making, economic redistribution, and kleptocratic religion don’t just develop automatically through a Rousseauesque social contract. What drives the amalgamation?
In part, the answer depends upon evolutionary reasoning. I said at the outset of this chapter that societies classified in the same category are not all identical to each other, because humans and human groups are infinitely diverse. For example, among bands and tribes, the big-men of some are inevitably more charismatic, powerful, and skilled in reaching decisions than the big-men of others. Among large tribes, those with stronger big-men and hence greater centralization tend to have an advantage over those with less centralization. Tribes that resolve conflicts as poorly as did the Fayu tend to blow apart again into bands, while ill-governed chiefdoms blow apart into smaller chiefdoms or tribes. Societies with effective conflict resolution, sound decision making, and harmonious economic redistribution can develop better technology, concentrate their military power, seize larger and more productive territories, and crush autonomous smaller societies one by one.
Thus, competition between societies at one level of complexity tends to lead to societies on the next level of complexity if conditions permit. Tribes conquer or combine with tribes to reach the size of chiefdoms, which conquer or combine with other chiefdoms to reach the size of states, which conquer or combine with other states to become empires. More generally, large units potentially enjoy an advantage over individual small units if—and that’s a big “if”—the large units can solve the problems that come with their larger size, such as perennial threats from upstart claimants to leadership, commoner resentment of kleptocracy, and increased problems associated with economic integration.
The amalgamation of smaller units into larger ones has often been documented historically or archaeologically. Contrary to Rousseau, such amalgamations never occur by a process of unthreatened little societies freely deciding to merge, in order to promote the happiness of their citizens. Leaders of little societies, as of big ones, are jealous of their independence and prerogatives. Amalgamation occurs instead in either of two ways: by merger under the threat of external force, or by actual conquest. Innumerable examples are available to illustrate each mode of amalgamation.
Merger under the threat of external force is well illustrated by the formation of the Cherokee Indian confederation in the U.S. Southeast. The Cherokees were originally divided into 30 or 40 independent chiefdoms, each consisting of a village of about 400 people. Increasing white settlement led to conflicts between Cherokees and whites. When individual Cherokees robbed or assaulted white settlers and traders, the whites were unable to discriminate among the different Cherokee chiefdoms and retaliated indiscriminately against any Cherokees, either by military action or by cutting off trade. In response, the Cherokee chiefdoms gradually found themselves compelled to join into a single confederacy in the course of the 18th century. Initially, the larger chiefdoms in 1730 chose an overall leader, a chief named Moytoy, who was succeeded in 1741 by his son. The first task of these leaders was to punish individual Cherokees who attacked whites, and to deal with the white government. Around 1758 the Cherokees regularized their decision making with an annual council modeled on previous village councils and meeting at one village (Echota), which thereby became a de facto “capital.” Eventually, the Cherokees became literate (as we saw in Chapter 12) and adopted a written constitution.
The Cherokee confederacy was thus formed not by conquest but by the amalgamation of previously jealous smaller entities, which merged only when threatened with destruction by powerful external forces. In much the same way, in an example of state formation described in every American history textbook, the white American colonies themselves, one of which (Georgia) had precipitated the formation of the Cherokee state, were impelled to form a nation of their own when threatened with the powerful external force of the British monarchy. The American colonies were initially as jealous of their autonomy as the Cherokee chiefdoms, and their first attempt at amalgamation under the Articles of Confederation (1781) proved unworkable because it reserved too much autonomy to the ex-colonies. Only further threats, notably Shays’s Rebellion of 1786 and the unsolved burden of war debt, overcame the ex-colonies’ extreme reluctance to sacrifice autonomy and pushed them into adopting our current strong federal constitution in 1787. The 19th-century unification of Germany’s jealous principalities proved equally difficult. Three early attempts (the Frankfurt Parliament of 1848, the restored German Confederation of 1850, and the North German Confederation of 1866) failed before the external threat of France’s declaration of war in 1870 finally led to the princelets’ surrendering much of their power to a central imperial German government in 1871.
The other mode of formation of complex societies, besides merger under threat of external force, is merger by conquest. A well-documented example is the origin of the Zulu state, in southeastern Africa. When first observed by white settlers, the Zulus were divided into dozens of little chiefdoms. During the late 1700s, as population pressure rose, fighting between the chiefdoms became increasingly intense. Among all those chiefdoms, the ubiquitous problem of devising centralized power structures was solved most successfully by a chief called Dingiswayo, who gained ascendancy of the Mtetwa chiefdom by killing a rival around 1807. Dingiswayo developed a superior centralized military organization by drafting young men from all villages and grouping them into regiments by age rather than by their village. He also developed superior centralized political organization by abstaining from slaughter as he conquered other chiefdoms, leaving the conquered chief’s family intact, and limiting himself to replacing the conquered chief himself with a relative willing to cooperate with Dingiswayo. He developed superior centralized conflict resolution by expanding the adjudication of quarrels. In that way Dingiswayo was able to conquer and begin the integration of 30 other Zulu chiefdoms. His successors strengthened the resulting embryonic Zulu state by expanding its judicial system, policing, and ceremonies.
This Zulu example of a state formed by conquest can be multiplied almost indefinitely. Native states whose formation from chiefdoms happened to be witnessed by Europeans in the 18th and 19th centuries include the Polynesian Hawaiian state, the Polynesian Tahitian state, the Merina state of Madagascar, Lesotho and Swazi and other southern African states besides that of the Zulus, the Ashanti state of West Africa, and the Ankole and Buganda states of Uganda. The Aztec and Inca Empires were formed by 15th-century conquests, before Europeans arrived, but we know much about their formation from Indian oral histories transcribed by early Spanish settlers. The formation of the Roman state and the expansion of the Macedonian Empire under Alexander were described in detail by contemporary classical authors.