Robert D. Drennan Distinguished Professor

3302 WWPH

Robert Drennan is an archaeologist engaged in the comparative analysis of early complex societies from their beginnings in characteristics humans share with many other species to the enormous diversity of organizational patterns displayed by regional chiefdoms around the world. Topics emphasized in his research include regional settlement and demography, community structure at all scales, household archaeology, quantitative data analysis, spatial analysis, and GIS. These topics are all involved in his fieldwork in China, Mesoamerica, and northern South America.

Comparative Analysis of Early Complex Societies

"The impulse toward increasing demographic scale … manifested itself repeatedly. Growth was neither steady nor uninterrupted, but region after region experienced episodes of often dramatic increase. This is not surprising for a biologically successful species that, as of ten thousand years ago, had just spread itself through all the world's major land masses. Higher regional population densities brought larger numbers of people into closer patterns of interaction than ever before, and new social relationships were organized in increasingly complex ways, very frequently in hierarchical forms of organization. Hierarchy is, after all, a highly effective principle of organization, and it is clear that the biological basis for hierarchical organization of small social groups was present in early humans, as in many other species. Cultural variability in the expression of such tendencies may exist in nonhuman species as well. These broadly similar trends toward demographic growth and more complex and varied, often hierarchical, organization are thus not difficult to understand." (Drennan and Peterson 2012: 63–64)

"The sample of [archaeologically known] chiefdoms is large enough, not only to force us to notice how varied these societies are, but to give us a chance to find patterns in this variability. If such patterns can be discovered, it suggests that the variability is not just idiosyncratic and random, but rather that the forces of social change tend generally to operate in a limited number of consistent ways that we can potentially specify. The available archaeological information about trajectories of chiefdom development in many regions is now becoming adequate to sustain such research. It can proceed from abstract models toward empirical data or in the reverse direction: models that make sense can be evaluated by seeking the patterns they lead us to expect in chiefdom variability, or chiefdom variability can be explored for patterns that can be the basis for formulating new models. Productive research is likely to work back and forth between models and empirical patterns." (Drennan and Peterson 2012:64–65)

Robert D. Drennan and Christian E. Peterson

2012 Challenges for Comparative Study of Early Complex Societies. In The Comparative Archaeology of Complex Societies, edited by Michael E. Smith, Cambridge University Press.

"Public works were supported by tax rates that remained quite low throughout five trajectories, both because social formations grew in scale and because regional populations increased. These are Marana, the Basin of Mexico, the Tehuacán Valley, the Middle Niger Delta, and the Alto Magdalena. Three other regional trajectories (Oaxaca, Western Liao, and Shandong) are also consistent with this account. In these latter three sequences, a perceptible rise in tax rates is followed in the next period by both regional population growth and the emergence of substantially larger social formations. These new social formations carried out public works projects of unprecedented scale in their regions with tax rates that had fallen back into the lowest category. This combination of the motivations of self-aggrandizing elites, resistance, the social and practical functions of public works, and mobilization of labor makes sense of a pattern of growth that seems recurrent among this dozen trajectories at least." (Peterson and Drennan 2012:125)

Christian E. Peterson and Robert D. Drennan

2012 Patterned Variation in Regional Trajectories of Community Growth. In The Comparative Archaeology of Complex Societies, edited by Michael E. Smith, Cambridge University Press.

"These multidimensional scaling analyses of household assemblages … show differences between the communities analyzed in terms of the organization of status, wealth, and economic and ritual specialization. Fábrica San José shows the strongest and clearest patterns, even though it was only a small subsidiary community in its region. The patterns it shows, moreover, are those often taken as prototypical of chiefdoms: a single clear dimension of social ranking, unequivocal craft specialization, and a connection between the two in that most craft specialist households had relatively high status. At Fushanzhuang, several different kinds of productive specialization are clear but not as strongly developed as those of Fábrica San José. Two principal indicators of ranking show clear but separate trends to suggest two separate hierarchies, one of wealth and an uncorrelated one of social status. Wealth seems connected to specialization, but status does not. … Jenné-Jeno has by far the largest population of all five communities analyzed here, but household assemblages do not show any clear patterns of status or wealth differentiation, consistent with what has previously been written about it (McIntosh 2005). Both textile work and iron-making are clearly in evidence, although the artifact assemblage evidence of craft specialization must be counted as weaker than at the very small communities of Fábrica San José or Fushanzhuang. Specialization and social hierarchy are both present in the household assemblages from Mesitas, but they seem weakly developed, despite the impressive burials of the Alto Magdalena. This kind of surprise did not emerge from the household assemblage analysis for the two extremely small Wankarani communities; the weakness of evidence for social ranking in the artifact assemblages parallels the conclusion drawn from the burial evidence." Drennan, Peterson, and Fox 2010:61–62)

Robert D. Drennan, Christian E. Peterson, and Jake R. Fox

2010 Degrees and Kinds of Inequality. In Pathways to Power edited by T. Douglas Price and Gary M. Feinman. Springer.

The overall impact of the Alto Magdalena's monuments is to focus attention strongly on specific individuals, who may well be represented in the large sculptures incorporated into the barrows and the plazas adjoining them. The sculptures combine human and animal characteristics in clearly supernatural references, as in human faces with fangs or two-headed reptiles on the backs of human figures. These themes recall ethnographically known shamanic beliefs in supernatural power involving human-animal transformations. The monument complexes range from small (a single mound and a few statues) to large (several large mounds and dozens of statues on adjacent hilltops) and are widely distributed across the Alto Magdalena. The ceremonial activities carried out at the monuments and the hierarchical social relationships they express so conspicuously seem the central elements in regional-scale social integration. The multiple regional-scale chiefly communities of the Alto Magdalena are, in this respect, very much like the lone San José Mogote district in Oaxaca.(Drennan and Peterson 2006:3961)

Robert D. Drennan and Christian E. Peterson
2006 Patterned Variation in Prehistoric Chiefdoms. Proceedings of the National Academy of Sciences 103:3960-3967.

Early Complex Societies in Colombia

The chiefdoms of the Valle de la Plata turned out to be very largely a phenomenon of the higher elevations represented by the western survey zone. It was in this survey zone where the regional settlement evidence enabled the clearest definition of districts—-human interaction communities of the Regional Classic period that each comprised a few thousand inhabitants in an area 10–15 km across. Each of the Regional Classic districts had a single complex where a small number of extremely highly regarded individuals were buried in monumental tombs surrounded by carved stone statues. Closely surrounding this complex was a core area of concentrated population. Moving out from this central core, the density of occupation steadily diminished, with households located farther and farther apart on the landscape. Eventually the spacing between households began to decrease again, as the core area of the next district was approached. The particular activities most in evidence for providing a central focus and an identity to these large scale centralized human communities were the burials and permanent monumental commemoration of specific important individuals. (Drennan 2006:219)

Robert D. Drennan, ed.
2006 Prehispanic Chiefdoms of the Valle de la Plata, Vol. 5: Regional Settlement Patterns. University of Pittsburgh Memoirs in Latin American Archaeology, No. 16, p. 219.

La construcción del Montículo Occidental de la Mesita A [en San Agustín] con su tumba principal y varias estatuas asociadas posiblemente ocupó los esfuerzos de unos 15 trabajadores durante un mes y medio. Definitivamente no tenemos que pensar en la organización de un cuerpo de cientos de hombres durante varios años—simplemente no es una obra pública de tal escala. Drennan 2000:20–22)

The construction of the West Mound of Mesita A [in San Agustín], with its main tomb and several associated sculptures might have required the labor of some 15 people for about a month and a half. We definitely do not have to imagine organizing a force of hundreds of laborers for some years—it simply is not a work on such a scale. (Drennan 2000:20–22)

Drennan, Robert D.
2000 Las Sociedades Prehispánicas del Alto Magdalena. Bogotá: Instituto Colombiano de Antropología e Historia.

Taking three different approaches to characterizing the distribution of environmental characteristics as related to agricultural productivity, then, we repeatedly failed to find a consistent relationship between density of Regional Classic occupation and either agricultural productivity or any specific environmental conditions. It is not the case that population tended to concentrate in certain areas simply following the uneven spatial distribution of agricultural productivity. This, of course, is not to say that the settlement concentrations existed and were located with no reference whatever to environmental parameters, but rather that they appear to owe their existence more to social and/or political factors than to strictly environmental ones.

Robert D. Drennan and Dale W. Quattrin
1995 Social Inequality and Agricultural Resources in the Valle de la Plata, Colombia. In Foundations of Social Inequality, edited by T. Douglas Price and Gary M. Feinman, Plenum Press, p.220.

The individuals buried in the Valle de la Plata's elaborate tombs seem most likely to have been the leaders (or "chiefs") of these societies.... The monumental nature of these burials made an emphatic and permanent statement about the importance of the individuals so commemorated.

Robert Drennan
1995 Tombs for the Living: Andean Mortuary Practices, Dumbarton Oaks, p. 94.

Early Complex Societies in Northeastern China

"Here we compare the separate trajectories of social change of the Yuncheng Basin and the Chifeng region through the Neolithic and into the beginning of the Bronze Age of northern China. As a matter of general reference, the trajectories we compare fall in the realm of chiefdom and state emergence, although these typological constructs are not the principal conceptual tools we employ. … Our focus is on the nature and scale of human social communities, both local and regional. It is this element of these two trajectories that regional settlement studies are now enabling us to reconstruct much more fully than ever before. … In order to carry out the substantive comparison of the changing human communities of the two regions, we also explore the implications of differing field and analytical methods." (Drennan and Dai 2010:455–456)

Robert D. Drennan and Xiangming Dai

2010 Chifedoms and States in the Yuncheng Basin and the Chifeng Region: A Comparative Analysis of Settlement Systems in North China. Journal of Anthropological Archaeology 29:455–468.

A mathematically smoothed surface of Hongshan occupation in the Dongshanzui survey area (Fig. 6) shows settlement clustering that suggests four distinct supralocal communities or districts into which the approximately 100 local communities group themselves. A fifth district may be represented by the Hongshan occupation in the separate 5-km2 survey area to the north in Fig. 5. This aspect of regional organization, like the nature of local communities, is similar to what was found in the Chifeng survey. In both regions, larger, somewhat denser, and more closely spaced local communities are at the heart of each district. Farther out, more scattered occupation creates sparsely settled buffer zones that separate the districts.

Peterson, Christian E., Xueming Lu, Robert D. Drennan, and Da Zhu. 2010. Hongshan Chiefly Communities in Neolithic Northeastern China. PNAS 107:5756-5761.

In the central portions of each of the four districts are definite or probable remains of Hongshan ceremonial architecture, still visible on the surface even some 6,000 years later (Fig. 7). One of these locations is, of course, the excavated ceremonial complex of Dongshanzui. All four districts in the large survey area also have centrally located collection units with large quantities of the painted pottery cylinders that characteristically adorned Hongshan burial platforms, even though no architectural remains are visible on the surface today in these particular locations (Fig. 7). The Dongshanzui survey area thus provides direct documentation of core zone monuments in central locations in small supralocal communities—just the social setting imagined for them with inspiration from communities in the periphery. The Dongshanzui survey area manifests the more developed character of core zone monumentality: the monuments aremore numerous,more elaborate,more varied, andmore densely distributed on the landscape than in the periphery.Their social roles and contexts, nonetheless, seemvery like those of the lessimpressive monuments of Chifeng.

Peterson, Christian E., Xueming Lu, Robert D. Drennan, and Da Zhu. 2010. Hongshan Chiefly Communities in Neolithic Northeastern China. PNAS 107:5756-5761.

"Systematic" collecting has come to refer in archeology to the practice of carefully collecting all artifacts within a clearly delineated area. Such a procedure reduces sampling bias because survey crews exercise no judgement about what to collect and what not to collect, and because artifacts whose characteristics make them inconspicuous are less likely to be overlooked when the ground surface in a small area is examined very carefully. Although such techniques have been used in many contexts, large-scale regional surveys are often carried out without systematic collection because the practice is thought to be too time-consuming to be practical on this scale. In Chifeng, however, we have found making systematic collections eminently practical. Two members of a survey crew can mark out a circle 3 m in diameter very quickly. (One stands still holding one end of a 1.5 m rope while the other holds the other end and walks around in a circle making boot marks on the ground.) All artifacts within the circle are collected (it usually takes less than ten minutes). If fewer than 20 sherds are found, then additional adjacent circles are collected until the minimum sample size is achieved, and the total number of circles serves as a record of the area within which the systematic collection was made so that the average number of sherds (or artifacts of any kind) per m2 can be calculated. (Drennan et al. 2003:137)

Drennan, Robert D., Christian E. Peterson, Gregory G. Indrisano, Teng Mingyu, Gideon Shelach, Zhu Yanping, Katheryn M. Linduff, and Guo Zhizhong)
2003 Methods for Archeological Settlement Study. In Regional Archeology in Eastern Inner Mongolia: A Methodological Exploration /. Beijing: Science Press. (Clinton Corners, NY: Eliot Werner Publications)

As we look at the increasingly smoothed surfaces [of the Chifeng Hongshan occupation], we … see the emergence of spatial structure at a larger scale. At a power of 2, small basal flanges begin to appear around the occupational peaks. These broaden at a power of 1 into distinctly funnel shapes which might help us define the more inclusive clusters … [we] take as communities as well, in the same social interaction sense as we have used the word "community" before, but at a larger scale than the small local communities already defined.

Peterson, Christian E., and Robert D. Drennan
2005 Communities, Settlements, Sites, and Surveys: Regional-scale Analysis of Prehistoric Human Interaction. American Antiquity 70.

Early Complex Societies in Mesoamerica

"Around Quachilco, the local community structure persisted most strongly in the southwestern part of the survey area where canal irrigation systems may have fostered local community interaction patterns. The structure dispersed most noticeably in the river bottom zone toward the northeast, where increased agricultural production may have been required to support a larger regional population, but where the manner of cultivation did not involve canal systems or any other technology encouraging local community interaction patterns. The shift in residence patterns that we have observed here could have weakened preexisting patterns of local community interaction and discouraged further development of whatever productive specialization already existed. At the same time, the weakening of interaction pathways structured in local communities would have impeded efforts by political elites at Quachilco to use a set of building blocks that might have served them well in developing the political economy to fund their ambitions." (Drennan and Haller 2007:80)

Robert D. Drennan and Mikael J. Haller

2007 The Local Village Community and the Larger Political Economy: Formative and Classic Interaction Patterns in the Tehuacán Valley Compared to the Valley of Oaxaca and the Basin of Mexico. In The Political Economy of Ancient Mesoamerica: Transformations during the Formative and Classic Periods edited by Vernon L. Scarborough and John E. Clark. University of New Mexico Press.

Excavations began with the cleaning and straightening of the walls of a stone quarry in the southwestern corner of the site. . . . This section of the site was designated Area A, and as soon as the sections of the profile had been photographed and drawn, several horizontal excavations were opened up, proceeding by natural stratigraphy back from the profile, where features such as house floors, burials, hearths, or bell-shaped pits of probable Middle Formative date were visible. . . . As excavations in Area A progressed . . . it was planned to excavate a series of test pits, beginning on the east side of the artificial mound and continuing to the east until the end of the Middle Formative deposits was reached.

Robert D. Drennan
1976 Fábrica San José and Middle Formative Society in the Valley of Oaxaca. Memoirs of the Museum of Anthropology, University of Michigan 8:12.

Robert D. Drennan, C. Adam Berrey, and Christian E. Peterson. 2015. Regional Settlement Demography in Archaeology. Clinton Corners, NY: Eliot Werner Publications.

Robert D. Drennan, Christian E. Peterson, Lü Xueming, Zhu Da, and Hou Shenguang. 2014. Settlement and Social Dynamics in the Upper Daling and Chifeng Regions of Northeastern China. Asian Archaeology 2:50–76.

Robert D. Drennan and Christian E. Peterson.  2012. Challenges for Comparative Study of Early Complex Societies. And Peterson and Drennan, Patterned Variation in Regional Trajectories of Community Growth. In The Comparative Archaeology of Complex Societies, edited by Michael E. Smith, pp. 62–87. Cambridge: Cambridge University Press.

Robert D. Drennan, Christian E. Peterson, and Jake R. Fox. 2010. Degrees and Kinds of Inequality. In Pathways to Power, edited by T. Douglas Price, pp. 45–76. New York: Springer. 

Lu Xueming, Christian E. Peterson, Robert D. Drennan, and Zhu Da. 2010. 辽宁大凌河上游流域考古调查简报. 考古 [Kaogu]: 2010(5):24–35. / 2010. Hongshan Chiefly Communities in Neolithic Northeastern China. PNAS 107:5756–5761. 

Robert D. Drennan and Christian E. Peterson. 2009. La Comunidad y el Cacicazgo: Un Estudio Comparativo de Patrones de Asentamiento Regional en el Alto Magdalena, el Valle de Oaxaca, y Mongolia Interior. In Economía, Prestigo y Poder: Perspectivas desde la Arqueología, edited by Carlos A. Sánchez, pp. 168–205. Bogotá: Instituto Colombiano de Antropología e Historia. / 2005. Early Chiefdom Communities Compared: The Settlement Pattern Record for Chifeng, the Alto Magdalena, and the Valley of Oaxaca. In Settlement, Subsistence, and Social Complexity: Essays Honoring the Legacy of Jeffrey R. Parsons, edited by Richard E. Blanton, pp. 119–154. Cotsen Institute of Archaeology, University of California, Los Angeles. / 2004. 早期酋长制群体的聚落形态比较研究以内蒙古东部,安第斯山北部和美洲中部三个地区为例. 吉林大学社会科学学报 [Jilin Daxue Shehuikexue Xuebao] 2004(5):15–31. 

2009. Statistics for Archaeologists: A Commonsense Approach. Second Edition. New York: Springer. 

2006. Prehispanic Chiefdoms in the Valle de la Plata, Volume 5: Regional Settlement Patterns / Cacicazgos Prehispánicos del Valle de la Plata, Tomo 5: Patrones de Asentamiento Regionales. University of Pittsburgh Memoirs in Latin American Archaeology, No. 16. 

Robert D. Drennan and Christian E. Peterson. 2006. Patterned Variation in Prehistoric Chiefdoms. PNAS 103:3960–3967. 

2000     Las Sociedades Prehispánicas del Alto Magdalena. Bogotá: Instituto Colombiano de Antropología e Historia. 

Michael E. Smith, Gary M. Feinman, Robert D. Drennan, Timothy Earle, and Ian Morris. 2012. Archaeology as a Social Science. PNAS 109:7617–7621.

Robert D. Drennan and Christian E. Peterson. 2012. Challenges for Comparative Study of Early Complex Societies. In The Comparative Archaeology of Complex Societies, edited by Michael E. Smith, pp. 62–87. Cambridge: Cambridge University Press.

Christian E. Peterson and Robert D. Drennan. 2012. Patterned Variation in Regional Trajectories of Community Growth. In The Comparative Archaeology of Complex Societies, edited by Michael E. Smith, pp. 88–137. Cambridge: Cambridge University Press.

The Chifeng International Collaborative Archaeological Research Project. 2011. Settlement Patterns in the Chifeng Region. Pittsburgh: University of Pittsburgh Center for Comparative Archaeology.

2011. El Área Intermedia, el Cacicazgo y la Investigación de la Dinámica del Cambio Social. In Arqueología en el Área Intermedia, edited by Víctor González Fernández, pp. 413–419. Bogotá: Instituto Colombiano de Antropología e Historia

Robert D. Drennan and Dai Xiangming. 2011. 运城盆地和赤峰地区的酋邦与国家—聚落系统的比较分析 [Chiefdoms and States in the Yuncheng Basin and the Chifeng Region: A Comparative Analysis of Settlement Systems]. 东方考古 [Dongfang Kaogu] 7:85–104

Drennan, R.D., Hanks, B.K., and Peterson, C.E. 2011. The Comparative Study of Chiefly Communities in the Eurasian Steppe Region. Social Evolution and History: Studies in the Evolution of Human Societies 10:149–186. Moscow: Uchitel Publishing House.

Robert D. Drennan, Christian E. Peterson, and Jake R. Fox. 2010. Degrees and Kinds of Inequality. In Pathways to Power, edited by T. Douglas Price, pp. 45–76. New York: Springer.

Lu Xueming, Christian E. Peterson, Robert D. Drennan, and Zhu Da. 2010. 辽宁大凌河上游流域考古调查简报 [Report on the Liaoning Daling River Basin Archaeological Survey]. 考古 [Kaogu]: 2010(5):24–35.

José Luis Lanata and Robert D. Drennan. 2010. Crossing Boundaries and Academic Fair Trade. In Voices in American Archaeology, edited by Wendy Ashmore, Dorothy Lippert, and Barbara J. Mills, pp. 73–93. Washington, DC: Society for American Archaeology.


Beginning as early as 10,000 years ago human communities of unprecedented scale began to emerge in many regions all around the globe. The process has continued in much more recent times as well. These larger communities, numbering at least a few hundred people, and ranging well up into the thousands, usually (but not always) became supra-local in character. Unequal, or hierarchical, relationships usually (but not always) came to occupy an important place in their social organization. The seminar takes a comparative approach to the social dynamics of this process, using the varied trajectories of chiefdom emergence in different parts of the world as an opportunity to increase our understanding of the forces that have driven this process and given the resulting societies such highly varied characteristics.

Regional Settlement, Communities, and Demography

In the absence of modern communication and transportation technologies, human social communities were constituted in patterns of interaction primarily at local and regional scales. Prehistoric interaction patterns are usually strongly reflected in the way in which a human population distributed itself across a landscape. Thus a central reason for studying ancient settlement patterns is to delineate communities in the past and reconstruct the ways in which they structured interaction of various kinds at different scales. Such an approach leads not only to purely social interaction but also to political organization and the organization of the production and distribution of goods. This seminar focuses on the social, political, and economic interpretation of regional-scale archaeological settlement patterns, once the patterns have been discerned through appropriate means of spatial analysis. All such interpretation rests finally on demographic reconstructions, so approaches to both relative and absolute demographic approximations at the regional scale are considered in depth. Finally, having discussed these features of ancient human organization that settlement analysis can tell us about, we consider how appropriate kinds of information to sustain such conclusions can be collected in the field.

Archeological Data Analysis I

An introduction to quantitative data analysis in archeology, this course covers basic principles of statistics, including exploratory analysis of batches, sampling, significance, t-tests, analysis of variance, regression, chi-quare, and estimating universe means and proportions from samples. The approach is practical, concentrating on understanding these principles so as to put them to work effectively in analyzing archeological data. Much of the statistical work is done by computer. Statistical principles are dealt with in the weekly class, computer applications in the weekly lab. No previous computer experience is required, and no previous math beyond high school algebra is needed. Familiarity with archeology, however, is assumed. This course is open only to graduate students and anthropology majors who are concentrating in archeology and have previously taken other courses in archeology.

Archeological Data Analysis II

Advanced analysis of archeological data, primarily quantitative. This course carries on where the discussion of basic statistical comparison and contrast of artifacts, features, assemblages, and sites in Archeological Data Analysis I leaves off. Topics covered include sampling, data base management, analysis of spatial distributions (GIS), computer graphics, and multivariate statistics such as factor analysis, multidimensional scaling and clustering.