Tuesday, July 21, 2015

Collapse or Longevity? Failure or Success?

When many people think of the ancient Maya, the term "collapse" often comes to mind. The Mayas were a group that were around for a while, but then collapsed. Archaeologists have spent a lot of time (and a lot of fieldwork and publications) trying to figure out how or why (or sometimes, whether) the Maya collapsed. If they collapsed, there must have been something wrong with Maya society, right? But the Maya cities lasted for some seven centuries before they were abandoned. Think about it. Seven hundred years. Were the Maya a failure (they collapsed), or were they a spectacular success (they lasted 700 years).

The idea that something must have been wrong with ancient cities or civilizations to make them collapse is a popular notion. And while it is a valid question to ask how or why a society like the Classic Maya collapsed, any such question should be paired with a consideration of just how long they managed to thrive. This collapse bias surfaced again today in a paper just posted in the Proceedings of the National Academy of Sciences:  "Human domination of the biosphere: Rapid discharge of the earth-space battery foretells the future of himanking" by Rohn R. Schramski, David K. Gattie and James H. Brown. This is a fine paper, about the global chemical energy supply on earth, and how it is being depleted at an incredibly fast rate right now. But they had to throw in a dig at ancient societies:

At local and regional scales, many multiple past civilizations (e.g., Greece, Rome, Angkor Wat, Teotihuacan) failed to adapt to changing social and ecological conditions and crashed catastrophically
Let's take a different look at those four ancient societies in comparison to contemporary nation-states:
 

So, which of these societies seem successful, and which ones seem too young to judge? I am dating the start of the European nation-states to 1648, the signing of the Treaty of Westphalia which created the modern system of nation-states. If European nations manage to survive another half century or so, they will have matched the longevity of ancient Greece (I am using the Classical and Hellenistic periods here). And if they last another 350 years they will match those failed collapsers, the ancient Maya.

I am the last one to deny the significance of the Classic Maya collapse. I think the revisionists who claim that they didn't really collapse are just plain wrong (see some of my posts on Publishing Archaeology about this, such as this one about Jared Diamond and his critics). But if the Maya managed to thrive in the jungle for seven centuries, maybe that fact should outweigh their eventual collapse. They spent centuries doing many things right, and then they got trapped for a few crucial decades and collapsed.

I will just chalk up the collapse quote above to the fact that scholars outside of history and archaeology tend to be clueless about ancient societies. I think the authors of the new paper are correct when they claim that ancient collapses "are of questionable relevance to the current situation." Much as I'd like to believe that the sustainability (or lack thereof) of ancient societies might have lessons for us today, in fact the technological, energetic, and demographic situation today is radically different from that of ancient societies like the Maya. I do think that ancient cities and societies have lessons for us today, and that is a major theme of this blog. But the nature of overall societal sustainability may not be one of those lessons.

Friday, July 17, 2015

Can we decipher the "meaning" of ancient buildings?

Many people wonder about the "meaning" of ancient buildings and sites. Why was the Pyramid of the Sun at Teotihuacan built? Was it dedicated to a specific god? What meaning did it have to the people who built it, and those to witnessed ceremonies there for centuries afterword? I am a skeptic about talk of ancient "meanings" of this sort (see a previous post about high-level meanings.) I agree with my colleagues Kent Flannery and Joyce Marcus (1993) that this kind of religious symbolism and meaning cannot usually be deciphered without written texts that explain ancient myths and beliefs. There are no such texts from Teotihuacan, so it is unlikely that we can figure out just what this pyramid meant in ancient times. But we do have some clues. This position is explained in general terms by architectural theoretician Amos Rapoport, one of the top scholars on wide urban topics and one of my heroes.
Amos Rapoport

Rapoport developed a very useful scheme of how architecture communicates information. He identifies three levels of communication in the built environment: high-level meanings, middle-level meanings, and low-level meanings (see Rapoport 1988, 1990). High-level meanings communicate messages of symbolism, cosmology, and religion. In ancient societies, these high-level meanings are typically understood by only a small number of specialists and elites; many commoners know little of them. High-level meanings are culturally-specific; for example, Egyptian symbolism is completely different from Mayan symbolism. Today, scholars can reconstruct high-level meanings only if there are explicit written texts, or in some cases, very rich archaeological finds.

Middle-level meanings communicate messages of power, control, stability, wealth, and other positive values that rulers and elites want their subjects to receive. These meanings are more general and widespread than high-level meanings. Big buildings signal power, whether in ancient Mesopotamia or Classical Rome. Because these messages are valid across cultures (and not culturally specific), archaeologists can often interpret them from the mute remains of ancient architecture.
The Aztec Templo Mayor in Tenochtitlan

Finally, low-level meanings concern the specific ways that people interact with buildings. They provide cues for how to behave appropriately, where to enter or exit, and other messages concerning movement, privacy, accessibility, and the like.


The Coyolxauhqui stone
The birth of Hutziliopochtli
I will illustrate Rapoport's scheme with the Aztec major temple, the "Templo Mayor" in their imperial capital Tenochtitlan (today the ruins are in the middle of Mexico City). It turns out that we have a good idea of the high-level meaning of this temple, mainly because of a key find of a stone monument, coupled with written evidence of Aztec creation myths. The monument, a stone slab some 10 feet in diameter, depicts the Aztec goddess Coyolxauhqui, who has been dismembered. It was excavated in front of the main front steps of the Templo Mayor. This monument illustrates the birth of the Aztec god Huitzilopochtli, whose first action after birth was to kill his sister Coyolxauqui (yes, that sounds odd; if you want the whole story, check one of the many books on the Aztecs, such as my book, The Aztecs). We know this myth from written sources, and from some early Spanish pictures (see the illustration from Sahagun's Florentine Codex). In terms of religious symbolism (high-level meaning), the Aztec main temple was a model of Serpent Hill, where their god Huitzilopochtli was born and killed his sister Coholxauhqui. The human sacrifices that took place on top of the Templo Mayor were re-enactments of Huitzilopochtli's birth.

The middle-level meanings of the Aztec Templo Mayor were messages of power and wealth. No other Aztec city had a pyramid this big, with such sumptuous offerings. The Aztec emperors were powerful, and the city and empire were wealthy. Visitors to the city from foreign lands may not have known the myth of Huitzilopochtli's birth, but they could clearly understand the middle-level messages being sent deliberately by the Aztec emperors through their main temple. The low-level meaning of the Aztec Templo Mayor concerned access to the temple: who could approach it, who could climb the steps, and what were people expected to do when they approached the building.
Feathered serpent temple, Teotihuacan

Let's return to Teotihuacan to see if we can glean any information about high-level meanings from the main temples. We lack the myths of the Aztecs, in written and painted form. But one of the main temples, the "Feathered Serpent Temple", was covered elaborate carved images. One of the key images is the feathered serpent, a major deity at Teotihuacan. So in this case we can suggest that this temple was dedicated to a particular god. But we can't say much more than that about it's high-level meanings.

A recent discovery at the Pyramid of the Sun at Teotihuacan furnishes a clue about possible high-level meanings at this largest temple. Archaeologists have known for some time that another major god at Teotihuacan was the "Old fire god," whose stone sculptures are often excavated in houses. A very large example was excavated a couple of years ago in the Pyramid of the Sun; the photo here shows archaeologists Alejandro Sarabia and Nelly Zoe Nuñez working on this find in the lab. While we are a long way from being able to show that rituals at this temple reenacted key myths (as at the Aztec case), this find does provide a clue about the possible symbolism (high-level meaning) of the Pyramid of the Sun. So while we are not "clueless" about the ancient symbolism of this structure, we really know very little about its high-level meaning. But its middle-level meanings are much clearer, as anyone who has approached the building from the west can attest. We can understand the power and wealth and stability communicated by this building, even if we know almost nothing of the culture, language, or myths of Teotihuacan.


If you want to learn more about the three levels of communication, the place to start is with Rapoport's publications. I discuss them in several papers, and Flannery and Marcus discuss very similar ideas. There are several levels of meaning in the wide urban world, and some are more accessible to us today than others.


References:

Flannery, Kent V. and Joyce Marcus
1993    Cognitive Archaeology. Cambridge Archaeological Journal 3: 260-270.

Rapoport, Amos
1988    Levels of Meaning in the Built Environment. In Cross-Cultural Perspectives in Non Verbal Communication, edited by Fernando Poyatos, pp. 317-336. C. J. Hogrefe, Toronto.

1990    The Meaning of the Built Environment: A Nonverbal Communication Approach. rev. ed. University of Arizona Press, Tucson.

Smith, Michael E.
2007    Form and Meaning in the Earliest Cities: A New Approach to Ancient Urban Planning. Journal of Planning History 6 (1): 3-47.

2011    Empirical Urban Theory for Archaeologists. Journal of Archaeological Method and Theory 18: 167-192.

2012    The Aztecs. 3rd ed. Blackwell Publishers, Oxford.




Friday, February 20, 2015

How do big cities differ from small cities (in the ancient past and today)?

Are big cities different from smaller cities mainly in their size? Or do they differ in other ways that go beyond simple population size? Recent research on urban scaling has answered this question definitively for contemporary cities. Large cities ARE different from smaller cities in ways that transcend their size. They aren't simply larger. Yet many of the changes that come with size turn out to be linked systematically to population size.

For example, large cities of course have more miles of roads and and electrical cables than smaller cities. But when we look at roads or cable per person (miles per capita), the quantities are smaller for the biggest cities. This makes sense: if you have twice as many people in a city, you don't need twice as many roads, since some of the new people can use existing roads. While this much is obvious, quantitative research in urban scaling reveals a surprising finding: the way that the miles of roads per person changes with city size is extremely regular. The same quantitative relationship holds if you are studying cities in the U.S., in Europe, or other parts of the world. There is a basic underlying regularity to the quantities of urban infrastructures that get built and used, in cities all over the world.

Other types of regularities have been found by the urban scaling researchers. First, big cities have denser populations than smaller cities. One way to view this is that the areal extent of cities grows more slowly than does the population. The result is an increasing population density in larger cities. But again, this patterns is extremely regular and predictable mathematically. Second, the most remarkable regularity identified by urban scaling has to do with socioeconomic outputs. Whether you measure income, wealth, innovation, crime, poverty, or the number of rock bands, these features all increase more rapidly than does the population size. Big cities not only have more rock bands than smaller cities, but they have more rock bands PER PERSON than smaller cities. Furthermore, the mathematics are predictable. The rates of rock bands--or poverty, or patents--per person follow a very regular quantitative pattern.

Why is this? The basic idea is that as city population grows, so too does the number of social interactions among the residents and visitors to the city. But the number of potential  social interactions can increase at an exponential rate. And these interactions generate information and change. One basic metaphor is to say that cities are social reactors. They magnify the benefits (and negative consequences) of social interactions.

So far, I have been describing urban scaling research on modern cities. See the works of Luis Bettencourt and his colleagues listed below for more information, or see my earlier post on this research. But what about cities and settlements before the modern era? A new paper, published today, provides new evidence that similar predictable quantitative patterns are found in ancient cities. That is, Precolumbian settlements in central Mexico exhibit the same quantitative regularities in population density and social outputs as modern cities. Of course the society, the economy, and the nature of cities were very different back then. But still, the same quantitative patterns are present. To me, this is a remarkable finding.  The paper is:

Ortman, Scott G., Andrew H.F. Cabaniss, Jennie O. Sturm, and Luís M. A. Bettencourt   2015    Settlement Scaling and Increasing Returns in an Ancient Society. Science Advances 1(1).

This is an update and extension of their prior paper:


Ortman, Scott G., Andrew H.F. Cabaniss, Jennie O. Sturm, and Luís M. A. Bettencourt   2014   The Pre-History of Urban Scaling. PLOS-one 9 (2): e87902

The authors analyze settlement size and other data from the Basin of Mexico Archaeological Survey Project  (Sanders et al, 1979), and find that the quantitative patterns match those predicted by models of urban scaling that were first worked out for contemporary cities (Bettencourt 2013). I find this line of research fascinating, to the extent that I have been measuring cities and the sizes of their central plazas to investigate the quantitative pattern. It turns out that the size of the central plaza relates to the overall city size in a quite regular pattern, but the form of the equation does not match any of the quantities measured for modern cities. Hmmmmmmmm. I'll write more on this later.

For now, the new paper by Ortman et al is important for several reasons:

  1. It provides new data on quantitative patterns in the ancient cities and settlements of the Basin of Mexico.
  2. The results compare rather precisely to the predictions of the models and to the data on modern cities.
  3. This work shows the value of archaeological data for answering interesting questions about cities and urbanism in the past and the present. This only works when the original fieldwork was done well, and when the data are published and made available to other scholars.
Here are some publicity and news items about today's new paper:

An article by Emily Conover in Science Online

An article by Megan Gannon in LiveScience. 

Press release from the Santa Fe Institute


Bettencourt, Luís M. A.
2013    The Origins of Scaling in Cities. Science 340: 1438-1441.

Bettencourt, Luís M. A., José Lobo, Dirk Helbing, Christian Kühnert, and Geoffrey B. West
2007    Growth, Innovation, Scaling, and the Pace of Life in Cities. Proceedings of the National Academy of Sciences 104: 7301-7306.

Bettencourt, Luís M. A., José Lobo, Deborah Strumsky, and Geoffrey B. West
2010    Urban Scaling and its Deviations: Revealing the Structure of Wealth, Innovation and Crime Across Cities. PLoS One 5 (11): 1-9.

Sanders, William T., Jeffrey R. Parsons, and Robert S. Santley
1979    The Basin of Mexico: Ecological Processes in the Evolution of a Civilization. Academic Press, New York.


Monday, February 2, 2015

Three days in Teotihuacan

Big pyramid, little pyramid
I am posting from the Arizona State University archaeology facility in San Juan Teotihuacan, Mexico. I've just spent three days at the site of Teotihuacan, exploring the outer neighborhoods of the ancient city and learning about geophysical techniques applied to archaeology. I am considering using geophysics at Teotihuacan, so I came down to see Luis Barba and his team at work. Luis is collaborating with David Carballo, who has been working in the southern Teotihuacan neighborhood called Tlajinga, exposing apartment compounds by both excavation and geophysical prospecting. Check out his project website.

Geophysical prospecting is one of the "magical" tools available to archaeologists. We can see what lies beneath the ground surface without excavating.
Luis Barba with the gradiometer
Luis Barba (Instituto de Investigaciones Anthropológicas, Universidad Nacional Autónoma de México) is the leading archaoemetry specialist in Mexico (I can't get blogger to insert accents! Aaarghhh). He does geophysical research, archaeological chemistry of soils and artifacts, and other scientific studies. He and David spent the whole week doing geophysical work in the Tlajinga area, and I arrived Wednesday to see the fieldwork first-hand. Luis's team includes two members from his lab at UNAM: Jorge Blancas and Agustín Ortiz. Also, Meztli Hernandez Grajales of the Escuela Nacional de Antropologia e Historia, and Ashley Krauss of Yale University joined the crew for the week.The goal was to locate the outlines and some inner walls of apartment compounds in the Tlajinga area.

Me measuring electrical resistivity
Luis uses three main methods. The fastest method is magnetometry (see photo). They grid off a 20 by 20 meter square, and carry the instrument down the grid lines, taking four readings on the gradiometer per meter. This generates quantitative measurements of the magnetic properties of the subsoil, which is useful for archaeologists because the magnetic signatures of buried structures and features often contrast with the surrounding soil. The second method is electrical resistivity. Two probes are placed in the ground away from the sampling area, and then two metal probes are inserted into the ground at set intervals, again following the grid lines. Luis let me try this for a few passes (see photo). For these techniques, the data are uploaded, and maps can be generated very quickly to serve as guides to further steps.
Jorge Blancas & Ashley Krauss with the GPR unit

The most sophisticated and complicated geophysical technique is ground-penetrating radar ("GPR"). The device is dragged along the ground (the orange box in the photo), and a wheel records the distance traveled. The instrument sends radar waves into the ground, and registers the waves when they are reflected back up. GPR is far more sensitive and precise than the other methods, but it requires a large amount of processing and analysis after fieldwork is complete. While we could look at the day's magnetometry maps each evening, it takes much longer to make the GPR results available.

David, me, and Jorge with the GPS
The 20-meter survey blocks are aligned with the Teotihuacan grid, which means that they are aligned with the orientation of the ancient structures. The team uses a differential GPS unit to fix the precise location of the survey blocks. See the photo, with David and me standing around while Jorge works the unit.

I have always been fascinated by geophysical prospecting, but I haven't had the opportunity to use the methods in my research, and I didn't have up-close experience with the fieldwork. This was a great experience, and I am considering a possible fieldwork project with Luis and David, to expand their approach to other parts of Teotihuacan.
Street of the Dead in Tlajinga

Close-up showing the Moon pyramid
The Tlajinga neighborhood includes the central avenue at Teotihuacan, the Street of the Dead. In the main INAH archaeological zone, which is open to tourists, the street is paved, and lined with ceremonial structures. Down in Tlajinga it was evidently not paved, and was in fact a channel dug out of the underlying tepetate bedrock. This photo is looking north up the Street of the Dead from the Tlajinga area. You can just see the Moon Pyramid at the upper end of the street; I include a close-up from the center part of this photo with arrows pointing to the outline of the pyramid.

Reconstructed murals from Tetila

I also saw the excellent new museum,the Beatriz de la Fuente Museum of Teotihuacan Mural Paintings. In addition to having many of the actual wall paintings on display, several entire painted rooms are reconstructed at the museum. Also, the museum is integrated with a 3-temple group that was excavated a number of years ago (see the photo at the top of the post). These were probably neighborhood temples. The photo shows one of them, with the huge Pyramid of the Moon in the background.

I have been staying at the ASU archaeology facility in the town of San Juan Teotihuacan. This is a major storage facility, with many important artifact collections from Teotihuacan and nearby sites. There is space for artifact analysis, and living quarters for people using the lab or doing fieldwork.
Arizona State University lab facility at Teotihuacan

In the photo the two-story storage/analysis building is at the left. On the right are three small cabins with beds and bathrooms (I am staying in one of these). The doorway at the end of the driveway leads to the "Casa antigua," an old house that has bedrooms, a kitchen and common space, in addition to technical workspace and some storage. The tree behind the doorway is in the yard of the house.

Sunday, December 21, 2014

Medieval walls in modern Paris

Notre Dame de Paris
I just returned from 10 days in Paris and Bonn. One of the things I find amazing about cities in Europe is the way that ancient walls and buildings--whether Roman, Iron Age, or Medieval--have become part of the modern urban fabric. There are three ways that ancient architecture is manifest in modern cities. First, whole buildings have survived, and they continue to be used. Notre Dame cathedral, first built in the 12th century, is still an active church today, in addition to being a tourist destination. My wife and I visited many of these in Paris five years ago: St. Michel, St. Severin, the Cluny Abbey, and others.

Crypte Archeologique
A second way ancient buildings remain today is in the form of preserved ruins. This is what I am used to in Mexico. You can see the Aztec Templo Mayor in the middle of Mexico City, nicely preserved and set off from the modern city. In Paris, the whole open area in front of the cathedral has a preserved excavation underneath, the Crypte Archeologique du Parvis Nortre Dame is an amazing site (and sight), one of the highlights of our prior visit to Paris. Remains from Roman and Medieval Paris have been excavated and restored, and they are well labeled and explained. You walk right through the ruins, an impressive experience.

City wall of King Philip II
But the third way ancient buildings are preserved in modern cities is, for me, the most fascinating. This is when walls and parts of buildings have become incorporated into the historical and modern fabric of the city. I spent some time in Paris exploring this phenomenon. I began with an internet document, "Medieval Paris: A walking tour of the Marais," by Eric Jager. This is based on the north bank (rive droite), just across from Ile Saint-Louis. The tour takes you past the longest extent of the early medieval city wall, built in the 12th century by Philip II. Today, it separates some apartment buildings from a park, where kids were playing soccer.

Medieval street, recent buildings
The tour follows some winding streets that have preserved the old Medieval plan, although the buildings are much more recent. This view of Paris is radically different from the expansive boulevards created by Hausmann in the 19th century (see my prior post on this). The Champs Elysees is great, but I really enjoy walking through the old winding Paris streets.

Medieval arch, National Archives
The tour passes the National Archives building, which just happens to have a medieval archway with towers built into one side of it. There are a number of these cases on the walking tour. You look up an apartment building, perhaps 100 years old, and notice that one wall is more than 500 years old. Amazing.

I highly recommend this walking tour. The only problem is that it does not come with a map! The directions are good, and it was not hard to follow. I just printed out a Google map of the area before I left for Paris.

Roman amphitheater
I also ran into these medieval vestiges while walking around the city. I went to see the Roman Amphitheater, which has been restored in the middle of a block, with apartment buildings all around. Very interesting. Evidently Victor Hugo was instrumental in getting this excavated and restored in the 19th century. The Roman town was called Lutetia. On the way, I noticed a plaque on a building and learned that Rene Descartes had lived there for a few years.
Section of the medieval city wall

But I also ran into another portion of the old medieval city wall, where just a small segment was preserved at the edge of the street. And then after visiting the Shakespeare and Company book store, I spotted an old wall segment in a small park next to a medieval church.

The official component of my Paris trip was successful (Marion Forest passed her dissertation defense with highest honors, and I interacted with a bunch of friends and colleagues from the Universite de Paris-1, Pantheon-Sorbonne). But I was just amazed at all these vestiges of Medieval Paris that have become part of the modern urban landscape. Oh, by the way, the food was great too!
An old wall, probably medieval, near the Shakespeare bookstore

Wednesday, October 22, 2014

Living the good life in Teotihuacan

I have written two articles that contain new information about life in ancient Teotihuacan. These are scheduled to be published in November, but in the meantime I want to talk about some of the new findings and their implications. Teotihuacan had a unique form of urban life and society. I don't mean this in the sense that one can claim that every city is unique. What I mean is that Teotihuacan had several features that are VERY unusual for premodern cities. Here I will mention several of these features:

(1) Most residents lived in a form of housing that is unique among early cities of the world: the apartment compound. 
Apartment compounds.

Zacuala
There are over 2,000 apartment compounds at Teotihuacan. Although each one has a unique layout, most of them share features of their construction and layout. There is usually a single doorway in the stone outer wall. Entrances lead to a central open courtyard, which typically has some kind of temple or shrine or altar. Passages lead out from this to the individual apartments, which usually consist of a small open courtyard surrounded by rooms with porches.The courtyards are built at a lower level than the other rooms, and they are drained to the outside by pipes and channels under the floors. Floors and walls are covered with white lime plaster (technically, a form of concrete). The walls were usually painted with bright colors, with scenes of people, animals, and gods (see the image of Zacuala).
Oztoyahualco

My first article (Smith 2014) reviews the forms of urban housing used around the world before the Industrial Revolution. The various forms of housing are shown in the following typology:

Urban housing typology (Smith 2014)
Among all of the premodern cities of the world, the apartment building is the least common form of housing. Ancient Rome had apartment buildings (called insulae), as did some of the cities in the Ottoman Empire such as Cairo. But in those cases, apartments were small, cramped arrangements built to hold an overabundance of new urban immigrants. The Ottoman apartments often started out as large, spacious single-family houses that were subvided into many small apartments.

(2) Apartment compounds were luxurious and well-built.

The Teotihuacan apartment buildings are unusual (compared to Roman and Ottoman apartments) in
Aztec commoner houses
two ways. First, they are single-story structures. And second, each household had quite a bit of space, including a courtyard and several rooms with porches facing the courtyard. So these do not look like hasty buildings or conversions to accommodate an influx of new urbanites. They are spacious and open dwellings. When Laurette Sejourne excavated one of the first apartment compounds at Teotihuacan, she thought at first she had excavated a palace, and her name "Zacuala palace" is still used sometimes. In comparison with other ancient Mesoamerican patterns of housing, these structures do look like elite houses. Commoners, at other Mesoamerican cities, tended to live in small single-family houses.

In Aztec times, for example, there were a number of forms of commoner house (see the graphic, from the Florentine Codex by Sahagun), and I have excavated many of these structures. If I uncovered a Teotaihuacan-style apartment compound in an Aztec site I was excavating (and if it was indeed an Aztec structure, not an older pre-Aztec structure), I would call it an elite residence. The only Aztec houses this large, with this many rooms, and rooms this large, are elite residences. So while the overall form of a Teotihuacan apartment compound is not unique, it is very strange for a commoner house. Or was it an elite house? But you can't have most of the population as the elite? Or perhaps commoner and elite are not the best labels to use for the residents of Teotihuacan. This, again, is just plain bizarre for a Mesoamerican society. At just about all Mesoamerican urban sites, there are elite and commoner houses (typically at a ratio of ca. 50 commoner houses for every elite house), and it is rarely difficult to distinguish them.

(3) The apartment compounds appear to have been built in a single episode of urban renewal around A.D. 200.

Zacuala
Although we still have relatively few securely dated, excavated apartment compounds at Teotihuacan, it looks like most of them were constructed in a burst of activity around A.D. 200. In some of the excavated examples, there are irrigation canals below the floors, showing that the city expanded to cover former irrigated agricultural fields. We think that the houses before this episode were less regular, perhaps not conforming to the plans of apartment compounds. But in truth we know next to nothing about housing before this time. But why did the people or rulers of the city feel the need to obliterate older housing and agricultural fields to construct two thousand new apartment compounds?

(4) The level of social inequality was very low at Teotihuacan.


Tetitla
The second article that is now in press (Smith et al. 2014) is mainly about social inequality at Aztec sites. We illustrate the use of the Gini index to measure ancient social inequality, based on the sizes of houses. But while we were at it, we decided to try the method out on Teotihuacan. This required figuring out how the apartment compounds were divided into individual household dwellings. Student Rebecca Harkness took on this task, the the graphic shows her results for the Tetitla compound. We had to make some assumptions (e.g., that the excavated apartment compounds are representative of the unexcavated ones), and our result was very surprising.

The Gini index for Teotihuacan is 0.12, a very very low level for an urban settlement. This means that the level of inequality was quite low. All of the Aztec cities have higher values; the only site with a comparable value is a peasant village (Capilco). There are several reasons for such a low Gini index for Teotihuacan: (1) most houses were of a similar size; (2) there are a few smaller structures (probably adobe huts), and a few larger structures, but no huge royal palace. Yes, I know, some colleagues don't agree, and they have tried to identify a royal palace at Teotihuacan. But they can't agree with one another, and if you can't agree about the royal palace, then there probably wasn't one. No one has to scrounge around to find the royal palace at Maya or Aztec cities; they are quite obvious, huge structures that are many times larger than the typical house.

Atetelco
So, what does all this imply about life in ancient Teotihuacan? I think it is still too early to come to firm conclusions here. We need more excavations (several projects are ongoing at Teotihuacan right now, including work by by ASU colleague Saburo Sugiyama, and a project direct directed by David Carballo of Boston University). We need more studies of the already-excavated examples; ASU student Melissa Marklin is working on this now. I am not the first one to suggest that life and society at Teotihuacan were very different from other Mesoamerican societies, and from other cities around the world. Rene Millon and George Cowgill have talked about this, and Esther Pasztory has called Teotihuacan "an experiment in living."

Nevertheless, it seems clear that most people at Teotihuacan had large, spacious dwelling to live in. They had access to a wide range of household goods, for cooking, ritual, crafts, and other activities. There doesn't seem to have been a strong autocratic king ruling things, yet someone has enough clout to carry out a major urban renewal project. We can't find much evidence for a definite elite class. And people lived in a type of housing that was unique in the premodern world. What was going on at Teotihuacan? These facts remain disconnected and tantalizing, and we desperately need more research to figure things out. But I think we can conclude that people there were living the good life as part of the wide urban world.

Some links (ADDED Oct 24):

Prior post:  Teotihuacan: Ancient Mesoamerican Metropolis
Prior post:  Teotihuacan and the Origins of Market Economies

Project: Urbanism, Neighborhood Organization and Domestic Economy at the Tlajinga District, Teotihuacan. (current project by David Carballo, Luis Barba, and Kenneth Hirth)
  
The Teotihuacan Research Laboratory, Arizona State University

References


Carballo, David M.
2013    The Social Organization of Craft Production and Interregional Exchange at Teotihuacan. In Merchants, Markets, and Exchange in the Pre-Columbian World, edited by Kenneth G. Hirth and Joanne Pillsbury, pp. 113-140. Dumbarton Oaks, Washington, DC.

Cowgill, George L.
1997    State and Society at Teotihuacan, Mexico. Annual Review of Anthropology 26: 129-161.

Cowgill, George L.
2008    An Update on Teotihuacan. Antiquity 82: 962-975.

Millon, René
1976    Social Relations in Ancient Teotihuacan. In The Valley of Mexico: Studies of Pre-Hispanic Ecology and Society, edited by Eric R. Wolf, pp. 205-248. University of New Mexico Press, Albuquerque.

Pasztory, Esther
1997    Teotihuacan: An Experiment in Living. University of Oklahoma Press, Norman.

Smith, Michael E.
2014    Housing in Premodern Cities: Patterns of Social and Spatial Variation. International Journal of Architectural Research 8 (3): in press.

Smith, Michael E., Timothy Dennehy, April Kamp-Whittaker, Emily Colon, and Rebecca Harkness
2014    Quantitative Measures of Wealth Inequality in Ancient Central Mexican Communities. Advances in Archaeological Practice 2 (4): ___.

Sugiyama, Nawa, Saburo Sugiyama, and Alejandro Sarabia G.
2013    Inside the Sun Pyramid at Teotihuacan, Mexico: 2008-2011 Excavations and Preliminary Results. Latin American Antiquity 24 (4): 403-432.




Open Access week

This is open access week (Oct 20-24, 2014). For an interview I did on open access in publishing, CLICK HERE.

I will get back to posting on urban topics very shortly (sorry about the lapse).........