Part Of: Politics sequence
Content Summary: 2400 words, 12 min read

The Unilinear Stage Model

A polity is an identifiable political entity. Polities exhibit a remarkable degree of variation. Traditionally, four polity types been distinguished (Service 1962).

First, most human beings have lived in family-level groups (“bands”), about ~20 people living together. We’ve previously discussed the egalitarian ethos, which appears to have been maintained by a reverse dominance hierarchy. 

Second, some communities came together as local groups (“tribes”), often in the form of villages housing ~200 people. Villages often contain clans, each with ~30 people. Clans employ unilineal inheritance, emphasizing intensive kinship. Local groups with charismatic leaders were known as achievement-based societies, or Big Man groups. 

In some ways, it can be difficult to archaeologically differentiate tribes from bands (Renfrew 1974). Both show no evidence of differentiation among the buildings, no products of specialist craftsmanship, and a complete absence of grave goods which might indicate disparities in individual wealth.

Third, a rank society (“chiefdom”) is a collection of several villages. The village of the paramount chief village typically houses 1000 people. Leadership becomes inherited rather than earned. Social stratification and inequality emerge, often visible in grave burials. Warfare becomes more organized, and increasingly furthers economic goals (rather than more personal matters of homicide and infidelity).  With the advent of the warrior class, leadership styles transition from prestige towards coercion.

Many achievement-based societies destroyed a prominent man’s property at his death. But Carneiro (1949) notes that rank societies let the son inherit his father’s property, a key step in intergenerational inequality. Achievement-based societies brought captives home to torture or kill, and expel criminals. Rank societies like the Cauca considered prisoners and criminals a commodity, to be kept as slaves.

Fourth, a state (“kingdom”) is a collection of several chiefdoms. Such polities can house upwards of ~100,000 people. Bureaucrats began to administer the state, rather than simply kinship-based relationships. Finally, states feature cities with full-time specialists freed from the burdens of food production (specialization of labor; see Childe 1950). Warfare pivots towards conquest; tribute becomes taxation. 

The centralized, undifferentiated leadership style of chiefdoms had its limitations: a chief can only be at one location at a time. Archaeologically, the chiefdom is spatially limited to about a day’s walk, or 25 km (Spencer 1987). Due to this ceiling, after a certain point, conquest had limited marginal utility. By switching to centralized, differentiated leadership, states were able to transcend this constraint on size. However, differentiated leadership requires delegation, which increases the risk of usurpation. States first had to mitigate this usurpation threat before delegation became truly possible. 

Religious ritual changes dramatically across polity types. Family-level groups tend to place their huts in a circle, and conduct ad-hoc rituals in the common space. Local groups hold calendric rituals in men’s houses. Finally, chiefdoms de-emphasize men’s houses and instead use temples, which serve the elevated gods associated with the leadership clan.  In chiefdoms, sacred myths provide legitimation of authority. In many early states, the priesthood often plays a forceful role in leadership; this theocratic mode becomes less prevalent in more mature states (Webster 1976).

This tight relationship between cultural institutions and polity size is rather mysterious. Why are clans so pervasive in achievement-based societies, but less so for bands? Why do groups of ten thousand people invariably express inequality? Why do societies of one million people always require a bureaucracy? 

Check-List Archaeology

Anthropology provides rich synchronic data on modern-day political institutions. But ethnographies only go back a few decades or centuries. Archaeology provides sparse diachronic data on institutions across history. But we can use insights from anthropology to shed light on the past. 

With chiefdoms, polities began to span multiple settlements. If you first identify settlements with a shared material culture, and organize them by their population size, you’ll typically see a chiefdom comprising one large village, surrounded by multiple dependent hamlets. But some chiefdoms express a more complex settlement hierarchy, with a large village of the paramount chief, surrounded by medium-sized villages of the subchiefs, in turn surrounded by small hamlets. The number of levels in the settlement hierarchy is an indicator of polity type. A chiefdom is either a simple chiefdom (two administrative levels) or a complex chiefdom (three). A state is either an archaic city-state (four levels), all the way up to nation-state (arguably, six).

Burial rituals are useful indicators of social inequality. For example, in Europe during the Copper and Bronze Ages, dramatic changes in social differentiation took place throughout Europe. Sumptuary goods such as metal were used in burial rituals to advertise an individual’s personal wealth. When children are buried with such sumptuary goods, this is often taken as evidence of hereditary rank, since achievement-based societies often destroy the wealth of their Big Men upon death. But there are many other indicators of social inequality, such as energy invested in residential housing, and even variance of height as a window into access to nutritional variety (Boix & Rosenbluth 2014). 

Polity Ratcheting across History

One of the most dramatic trends in human history is polity ratcheting – polity size tends to grow. 

A corollary is that the number of independent polities tends to decline (Carneiro 1977). During Neolithic times, there were probably more than 100,000 independent political units of family or local group scale. Through expansion, conquest, incorporation, and treaties, this number has been reduced to roughly 160 nation-states today.

Since the speciation of Sapiens (~250 kya), humans lived in family-level groups. This polity type was favored through most of our history. Ratcheting is not observed. This did not change during the transition to behavioral modernity (~80-50 kya) or the emigration from Africa (~60 kya).

In the Ancient Near East, sedentism appears in the late Epipaleolithic (15 kya), and typically manifests in rich ecological zones with rich flora (e.g., in alluvial soil) and fauna (e.g., fishing sites).  These Natufian settlements supplemented hunting with abundant wild cereals. Settlements and ritual complexes (e.g., Gobekli Tepe) became more elaborate by the Pre-Pottery Neolithic. Only later at 9.5 kya does food production (agriculture and pastoralism) gain its stride. It took three more millennia for some of these societies to develop into states.

At first, growing crops and raising livestock did not have much of a perceptible effect on social structure. Small-scale societies of agriculturalists were nearly as egalitarian as small-scale societies of foragers. And those farming groups that stayed small-scale retained their resistance to hierarchy. In contrast, those societies that went down the path to civilization–growing large, acquiring cities, developing writing and extensive division of labor, and eventually becoming states–these societies became highly unequal, even despotic.

Egalitarian bands had less inequality and warfare than modern nation-states, but less public-good cooperation and more homicide. Political ideology biases us towards which of these considerations we find salient. Pro-state thinkers appeal to consent-based mechanisms of state formations; whereas anti-state thinkers are attracted towards coercive foundations. Discussions of social evolution tend to be muddied by ideological commitments. 

Economic Drivers of Social Evolution

There have been two subsistence modes in human history. Foragers who gather and hunt wild flora and fauna, and food producers, who use domesticated species. Within the food producers category, we see farmers who rely on domesticated plants, and pastoralists who rely on the meat and milk of domesticated animals. 

Larger polities require larger population densities, and larger population densities are only possible with a more productive subsistence economy. So it is not surprising that family-level groups were mainly foragers, and chiefdoms were mainly farmers. With each technological advance in subsistence, a wave of intensification occurs, and the ceiling of population density is raised. 

But the relationship between polity phase and subsistence mode is not deterministic! Some peoples like the Northwest Coast fishers, were hierarchical foragers – even holding slaves. And some farmers (particularly horticulturalists like the Machiguenga) lived in family-level groups (Johnson & Earle 2000).

Only in unusually productive ecologies that foragers are able to achieve population densities sufficient for chiefdoms. And even the richest natural environments are insufficient to fund a full-fledged state. States only emerge in agricultural centers.

In chiefdoms we see part-time specialists, and in states we see full-time craftsmen. Specialists depend on the food production of others. This is only possible if food producers can generate a surplus. Chiefdoms and states redirect this surplus towards public works and/or personal enrichment; this is the political economy (to be contrasted with the subsistence economy). 

Towards Evolutionary Anthropology

We can model social evolution as a Markov chain. Polities can undergo complexification (e.g., complex chiefdom → state) and simplification (state → complex chiefdom).  It is tempting to ascribe moral significance onto the direction of social evolution, but this practice isn’t particularly constructive.

Boasian anthropology vehemently rejected 1960-era cultural evolutionism. Some of this debate stems from different research styles:

• Anthropologists in the historical particularism tradition often use an idiographic style, focusing on properties unique to their case studies.
• Cultural evolutionists tend to use a nomothetic style, seeking to locate shared properties and to explain their emergence.

It is true that 1960s-era versions of cultural evolutionary theory were empirically impoverished, and tarnished by colonial ideologies of “savage to civilization” progress. But the field has matured since. Evolutionary typologies are often useful in facilitating cross-cultural research (Earle 1987).

Stage models are best couched with three disclaimers:

1. Some societies never undergo complexification beyond a certain level. The achievement-based societies of the Tewa, Hopi, Mandan, and Hidatsa of North America were extremely durable.  The Pueblo appear to have transitioned to chiefdoms in 900-1200 CE, but then inequality went into remission.
2. Social evolution is not unidirectional (with only complexification). We have seen societies transition between phases in phase cycling. Phase cycling especially gives a useful window into the dynamics of social evolution. 
3. Many societies blend elements across phases.  The Trobriand Islanders blended social conventions from both chiefdoms and Big Man collectives. Some villages in the Oaxaca Valley simultaneously housed men’s houses and temples, during their transition between phases.

Are phases arbitrary partitions of uniformly distributed social variables? Not necessarily. Technological shocks tend to elicit rapid change. This punctuationist data suggest the underlying variables are multimodally distributed. Further, transitions between phases may be unstable. In most chiefdoms, the inability to delegate power represents a geographical ceiling (half a day’s walk). Once delegation-enabling institutions were introduced by ambitious usurpers, polity size exploded upwards. 

Multilineal theorists suggest that there are other social structures besides the five already discussed. Renfrew (1974) first described group-oriented chiefdoms, or aristocracy without chiefs. One modern-day example comes from the Apa Tani near Tibet (Flannery & Marcus 2013; Ch13). These societies engaged in large-scale monumentalism (henges in England, statues in Easter Island) or multi-tiered settlement hierarchies (American Southwest), but did not feature appreciable inequality. 

We can generalize this into the network vs corporate dimension (Kowalewski 2000; Wason & Baldia 2000). Many large-scale polities encourage personal aggrandizement, concentrated wealth, and individual power. But some polities scaled up while retaining more egalitarian economic outcomes; these societies tend to share power, and place a heavier emphasis on ritual. 

Cultural Group Selection

Phase change can be bidirectional. So why does complexification tend to dominate over the long run? Why don’t we see this ballooning community size in the great apes, for example?

Cultural Group Selection (CGS) offers a framework for approaching this question.  While biological group selection is still disputed by evolutionary biologists, an emerging consensus is that group competition can occur on a cultural basis. Simply put, larger groups tend to outcompete smaller groups, and values and institutions that foster a competitive edge differentially survive. 

In many communities, selfish behavior pays off. Free-riders will invade any single population. But cooperative communities outcompete selfish ones. If between-group selection is strong, this can lead to a cooperative equilibrium. But, per the Price Equation, this outcome only works if the between-group variance is sufficiently high. Moralistic punishment serves to reduce in-group variation, and this human adaptation may have increased our capacity for group selection.

There are at least five different channels of intergroup competition (Henrich 2015):

A few general comments are in order:

• Intragroup cooperation (parochial altruism) generally tends to correlate with intergroup competition (xenophobia)  
• Intergroup competition likely intensified as population density rises.
• For small polities, non-coercive channels play center stage. Warfare dominates in later stages.

Larger groups win wars. “God is on the side of the big battalions”. Institutions that promote larger groups tend to replicate. This simple observation is the best explanation I know for polity ratcheting. Why do humans not live in chiefdoms anymore? Because states outcompeted them. 

Human Norms are Phase-Dependent

This suggests an intimate relationship between human norms and polity size. On the cultural evolutionary perspective, clannishness (tight kinship) is a package of cultural values selected to prevent fission, preserve group cohesion, and promote high fertility. Each polity phase becomes possible only with a set of values and institutions: 

• Morality is biologically innate, rudimentary law is an invention of chiefdoms.
• Speech is biologically innate, literacy is an invention of primary states.
• Spiritualism and symbolism is biologically innate, religion is an invention of primary states.
• Mate guarding is biologically innate, fraternal interest groups became more potent in achievement-based societies
• Dominance hierarchy is biologically innate, aristocracy is an invention of chiefdoms. 
• Stranger antipathy may be innate, but stranger tolerance emerges in the transition to states. 

The intimate relationship between values and social organization manifests in values revolutions linked to phase change:

• The Axial Age (fairness ethics and moralizing high gods) arrived at 600 BCE, with the emergence of the first mega-empires.
• The Enlightenment (modern science) arrived at 1700 CE, with the emergence of modern nation-states.

Does ideology have a retroactive legitimizing effect, or can it play a proactive role in facilitating conquest? The debate rages in many different historical circumstances. In the example of moralizing high gods, Purzychki et al (2016) argue for a proactive role, and Turchin et al (2023) argue the retroactive case. 

Until next time.

References

• Abrutyn & Lawrence (2010). From Chiefdom to State: Toward an Integrative Theory of the Evolution of Polity 
• Boix & Rosenbluth (2014). Bones of contention: the political economy of height inequality. 
• Childe (1950). The Urban Revolution
• Flannery & Marcus (2012). The Creation of Inequality: How our Prehistoric Ancestors set the stage for monarchy, slavery, and empire
• Henrich (2015). Secret of our Success: How Culture Is Driving Human Evolution, Domesticating Our Species, and Making Us Smarter
• Johnson & Earle (2000). The Evolution of Human Societies
• Korotayev (1995). Mountains and democracy: an introduction
• Kowalewski (2000). Cyclical transformations in North American prehistory
• Liverani (2008). The Shape of the Ancient Near East: Historical Overview
• Mulder et al (2009). Intergenerational Wealth Transmission and the Dynamics of Inequality in Small-Scale Societies
• Purzychki et al (2016). Moralistic gods, supernatural punishment and the expansion of human sociality
• Renfrew (1974). Beyond a subsistence economy: the evolution of social organization in prehistoric Europe
• Smith (2009). V. Gordon Childe and the Urban Revolution: a historical perspective on a revolution in urban studies
• Spencer (2010). Territorial expansion and primary state formation
• Turchin & Gavrilets (2009). Evolution of Complex Hierarchical Societies 
• Turchin et al (2023). Explaining the rise of moralizing religions: A test of competing hypotheses using the Seshat Databank.
• Wason & Baldia (2000). Religion, communication, and the genesis of social complexity in the European Neolithic