The site-size hierarchy concept, used to describe the origin and development of ancient states and chiefdoms, was born of a marriage between research interests in the emergence of complex societies and the mid-twentieth-century development of regional archaeological surveys. Prior to the mid-1950s the primary survey rationale was to locate sites for excavation; after the 1950s, surveys were designed to elicit information for a holistic approach that included the classification of regional political characteristics (e.g. Adams 1965; Willey 1953; McDonald and Rapp 1972). Researchers subsequently used survey data to address questions of cultural cohesion, ancient territorial integration, and the origins of the state with the assumption that large sites constituted the most 'important' loci for territorial social complexity and that administrative authority devolved along a linear gradient of progressively smaller settlements.
The site-size hierarchy concept has been so frequently used to describe the level of sociopolitical complexity of a given region that its referent often is uncited; indeed, the exact genealogy of the concept is somewhat difficult to elicit from the published record. Kent Flannery (1972) first called attention to the descriptive potential of the site-size rubric, noting that 'Wright (1969) has suggested that the appearance of a three-tiered administrative hierarchy with trimodal site sizes (city, town, and village) may be one indicator of state organization, taken in conjunction with other phenomena.'1 Flannery's mention of Wright's 1969 work focused on three site-size brackets (as did Johnson 1973, 15); Wright's own subsequent discussion of the concept indicates less stringent parameters, articulating the phrase 'three or more' in the definition of the state (Wright 1977, 389; see also Wright and Johnson 1975, 267); a decade later, this was augmented to specify not only site sizes but also a variety of qualitative criteria including administrative technology, public architecture, and iconography that signaled up to five tiers of control hierarchy (Wright 1986, 333–334). The general rule of thumb subsequently has infused the discussion of archaeological chiefdoms and states (e.g. Isbell and Schreiber 1978; Marcus and Feinman 1998, 6; Spencer 2003; Duffy 2015; Stanish 2020; Li et al. 2021).
Interestingly, the site-size hierarchy concept appears to be applied only in selective global cases, and that too within large, contiguous continental landmasses. Yet a site-size hierarchy can exist without any implication of an emergent polity, as seen for example in the case of the Bronze Age Indus culture in what is today western India and Pakistan. With only four (or perhaps, five) genuine urban centers and a gradation of other site sizes (Possehl 2002, 49; R. Wright 2010, 107), the Indus may well represent a situation in which there is a clear site-size hierarchy of four or five tiers that otherwise bears little evidence of state-like political cohesion (for comparative cases in the Americas and Papua New Guinea, see Duffy 2015). By contrast, some well-known states – such as the Roman or Qin that have such a range of site sizes that they might be described as a 6, 8 or 12-tier site-size hierarchy – are never quantified through the site-size rubric, an observation that reveals that the principal purpose of the clustering exercise is to enable lesser-known political regions to be definitively pronounced to be 'states' as part of processual classifications and evolutionary comparisons. Other caveats about the site-size hierarchy concept have been offered, ranging from unease about the reliability of the data about site sizes (usually predicated on the distribution of ceramics; Spencer 2009, 144) to a recognition that state-formation is a dynamic process with significant edge effects (Feinman and Nicholas 1990, 216–217) to the ontological challenge of utilizing quantitative rubrics to assess qualitative, dynamic human interactions (what Adam T. Smith critiques as a 'mechanical spatial ontology,' Smith 2003, 42).
What is needed beyond the site-size hierarchy model is a way to understand the internal dynamics and the mechanisms of growth, integration and change among sites through ongoing political interactions. Archaeologists have long recognized that site sizes do not always directly correspond to site importance in a regional configuration; that sites of smaller sizes can represent special-purpose functions not duplicated at larger sites (Flannery 1976, 170–171); and that sites of all sizes are dynamically linked in different ways at different times (Feinman and Nicholas 1990; Duffy 2015). Interpretations of ancient political connections have expanded beyond the notion of hierarchy to encompass concepts of heterarchy (e.g. Crumley 2015), 'distributed political influence' (Harrower and D'Andrea 2014, 532) and cooperation (e.g. Carballo, Roscoe, and Feinman 2014), providing the impetus to develop more realistic analytic models. Intellectual pathways for archaeological research come from other disciplines focused on complex systems in which the effects of hierarchy have been scrutinized and critiqued and in which a multiplicity of overlapping dynamics are evident (e.g. Appley and Winder 1977 for corporate life; Larsen 2008 for geography; Padial and De la Riva 2020 for biology).
Dynamism in complex societies
A focus on 'becoming' (sensu Gosden and Malafouris 2015) as a process of ongoing, dynamic interactions brings to the study of the state an electric potentiality of interpretation. Understanding state integration and disaggregation as an ongoing process is significant beyond achieving a better set of maps or more clearly delineating the types of ancient societies that can be grouped together into comparative studies of chiefdoms and states. Through the modeling of the iterative minutiae of contact and communication, we can broaden the focus of state interpretation from its longstanding emphasis on elites to include the entire diversity of human and non-human occupants. We also can provide the theoretical apparatus to focus on the smallest, most ubiquitous units of political action: the households and individuals whose autonomous interactions result in multilayered social configurations materialized in artifacts and architecture.
Individuals within political and environmental groupings are 'self-conscious' in their actions (Wengrow and Graeber (2015, 606), and their 'daily face-to-face interaction … is the matrix in which the growth of larger social formations takes place' (Drennan and Peterson 2012, 72). The result can be seen in the entire range of human activities, from the moment-by-moment actions of craft-making (e.g. Gosden and Malafouris 2015) through the materialization of landscape-level efforts of infrastructure, warfare and migration (e.g. Erickson and Walker 2009; Smith and Mohanty 2018). A theoretical apparatus of recursive interactions also engages with the non-human elements of daily life, including sentient and non-sentient life forms, the (deleterious or enhancing) effects of sites upon their environments and the differential impacts of natural disjunctions such as storms, earthquakes and plagues.
In the process archaeology envisioned by Gosden and Malafouris (2015), every human and non-human act is embodied in material expressions, and every action subsequently influences every subsequent action. The result is that archaeological sites are not merely discrete, bounded entities but are 'components of regional settlement systems characterized by distinctive site morphologies, land use strategies, and environmental relationships' (Casana 2007, 197). Site connections are sustained through physical and social pathways that shift and change as people establish new connections and abandon or avoid others (e.g. Carballo and Pluckhahn 2007; Hendrickson 2012). Pathways and their nodes are linked in many ways; while cities and other apex political centers may drive some types of political growth, they are not the exclusive locus of polity change and may not be the primary locus of political collapse (e.g. Feinman and Nicholas 1990, 237).
Three case studies: Siin West Africa, Angkor, Andean Moche culture
Three examples of the internal workings of complex societies illustrate the variability in social, economic, ritual and political configurations that necessitate recursive, dynamic models beyond site-size hierarchies.
The Siin region of West Africa in the mid-second millennium CE was characterized by a distribution of smaller and larger sites, but François Richard (2017, 211, 213) observes that these two-level site size hierarchies were nonetheless sophisticated beyond a village-and-hamlet binary because there were immaterial ways in which inhabitants expressed power, e.g. through people rather than monumental architecture, which means that we may not be able to see site 'sizes' or signs of visible labor investment in monuments as being the only yardstick of integrative iterations. He also suggests that due to the nature of cultivation and mobility, small settlements were short-lived (Richard 2017, 215), a factor that would overpopulate a map of site locations within broad chronological periods. Although seemingly simple, the two-tiered site size hierarchy in the Siin region supports the interpretive extrapolation of a variety of complex political configurations: a village-and-hamlet settlement configuration without any greater territorial political integration; a small chiefdom in the process of consolidating networks; a small chiefdom on the verge of collapse; a collapsed system with significant outside disruptions leading to settlement dispersal; and/or a steady and robust configuration characterized by bimodal site size distributions within distinct configurations of climate, agricultural production strategies, and transportation capacities.
Tegan Hall et al. (2016) provide an analysis of non-hierarchical dynamics in their analysis of the hinterlands of the second-millennium CE Angkor polity in Cambodia through a study of the site of Preah Khan, an iron-producing site located 100 km east of the political capital of Angkor. Evidence for Preah Khan's affiliation with the Angkorian polity is evidenced in the presence of temple complexes that closely follow the style and structure of royal architecture associated with the rulers Suryavarman II (1113–1150 CE) and Jayavarman VII (1182–1218 CE; Hall et al. 2016, 59), as well as the presence of a road network that linked Angkor with the site of Preah Khan (Hendrickson 2011). However, the differential timing of the temples, reservoir and iron production indicates that these were likely to have been sequential rather than simultaneous developments, and that the relationship between Preah Khan and Angkor was a dynamic one that changed over time. Even the 'collapse' of the Angkorian political realm was not a lockstep process with instantaneous effects on its surrounding network. Instead, researchers have found that there was a spike in charcoal at Preah Khan indicative of iron production in the waning days of Angkor, suggesting that the disarticulation of the polity was accompanied by resurgence in its hinterlands and that 'the apparent cessation of control by the political and economic elite based at Angkor appears to have occurred prior to the political abandonment of the capital in the early 15th century' (Hall et al. 2016, 62).
Edward Swenson's (2012) study of the Moche period (100–800 CE) incorporates excavation and survey data to show that population centers of the Jequetepeque Valley of Peru had differential investments in social and community activities as expressed in architecture and trash deposits. In particular, the 24-ha site of Huaca Colorada has evidence for very time-consuming ritual activities, including intentional burial and reconstruction of platforms and chambers. The intensity of ritual activities made Huaca Colorada prominent beyond the implications of its size, given that 'its spatial configuration, practices, and institutions seem to have diverged remarkably from other "centers" in the valley' (Swenson 2012, 22, citing Castillo, 2010). The investigator further concluded that 'the polycentric settlement system does not suggest a clear-cut hierarchy of sites and political institutions but points to alternative "constructions" of place and politics specific to Moche Jequetepeque' (Swenson 2012, 22). Just as Preah Khan was an important economic place that provided it with a special role, Huaca Colorada was an important ritual place with a special role in the Moche landscape; while each site was incorporated into a larger political configuration, it also had internal social dynamics and independent factors of change and stasis.
Alternative models
Gosden and Malafouris (2015, 701) discuss the process of 'becoming' as one that is more dynamic and intense than any single moment of 'being.' Applied to the development of social complexity in the form of chiefdoms and states, their concept of process archaeology (P-Arch) compels researchers to recognize that any single moment of activity that is materialized in an archaeological site represents a slice of reality within a longue durée of continuity and that complex societies are dynamic before, during and after the cartographic depiction of their unique moment of maximal size (cf. M.L. Smith 2005; Gosden and Malafouris 2015, 704).Five models from biology, engineering and computational sciences are proposed to understand the workings and implications of locational autonomy within larger systems by identifying the recursive elements characteristic of the process of 'becoming':
1) Reticulated hierarchies blend local autonomy with hierarchical linkages (Winder and Winder 2014; Figure 1).