Warfare in the Prehistoric Southwest

An Interview with Steven LeBlanc

ALTHOUGH MUCH OF THE GENERAL PUBLIC and many anthropologists view the ancient Puebloans as peaceful and having lived in harmony with their environment, archaeologists recently have shown increasing interest in warfare and social conflict in the prehistoric Southwest. In the following interview, Stephen LeBlanc discusses the kinds of archaeological evidence for such violence and addresses the underlying causes for the warfare in both climatic conditions and genetic tendencies.

The evidence for warfare comes primarily in four forms: settlement data, skeletal evidence, weaponry, and iconography. Settlement information involves defensive site location, architecture, and settlement patterns. Inaccessible rock shelters and mesa tops are examples of defensive sites, while high walls, towers, palisades, and moats represent defensive architecture. Settlement patterns include consolidation of small communities into larger pueblos, the aggregation of buildings into larger, more compact units, clustering of villages for common defense, line-of-site communication with other settlements, and the creation of no-man's-lands. Burned sites can give particularly compelling evidence for war. Skeletal evidence may involve fracturing and burning of bones, projectile points embedded in skeletons, and so on. Weaponry provides important evidence for warfare. Changes in weapons technology, such as the introduction of the recurved bow, often coincided with periods of increased warfare. Finally, iconography includes images of warfare on rock art, pottery, and kiva murals.

LeBlanc focuses on three prehistoric southwestern cultures: the Anasazis, who lived in the northern Rio Grande and Colorado Plateau regions and are believed to be the main ancestors of the modern Pueblo Indians; the Mogollons, who lived in a region in west-central New Mexico and in east-central Arizona below the Mogollon Rim that had been abandoned by the time of Spanish contact; and the Hohokams, who dwelled in the Salt River drainage of Arizona and are believed to be ancestral to the Pimas (Akimel O'odhams). While considerable evidence for warfare has been found in all three regions, the clearest evidence comes from the Anasazi area, especially after 1250 A.D.

Today Pueblo Indians are the cultural heirs of a tradition of farming villages dating back at least 1,500 years. LeBlanc identifies three distinct periods of the prehistoric Southwest and attempts to correlate warfare with climatic conditions. The Early Period, ranging from 200 to 900 A.D. (corresponding to the Basketmaker and Pueblo I period of the Anasazis), was a time of average climate. During this period, the Puebloans lived in small villages, practiced rudimentary agriculture, and engaged in extensive but small-scale warfare (raiding, ambush).

The Middle Period, from 900 to 1250 A.D. (the Pueblo II period), corresponded to the Medieval Warm Period when the worldwide climate was warmer and drier and hence more favorable for agriculture. Warfare in the Southwest decreased dramatically during this time. It was the era of the Chacoan Interaction Sphere, when Chaco Canyon was the center of an extensive system in which goods and information flowed between outlaying communities and the central canyon. In the various communities of the interaction sphere, large buildings (some known as "Great Houses") were surrounded by many smaller dwellings, indicating a social differentiation between an elite and commoners. The archaeology of this era gives evidence for cannibalism or at least for "extreme processing" of human corpses. LeBlanc does not believe that these were cases of starvation-induced cannibalism. Instead, he thinks that an elite group may have used terrorism to intimidate and control its populace. In any case, the existence of cannibalism does not provide evidence for intergroup warfare, which was minimal during the Middle Period.

The Chacoan system went into decline in the mid-1100s. During what LeBlanc calls the Late Period (1250 to 1500 A.D., the Pueblo III and IV periods), violence took place on a large scale. This occurred especially at the beginning of this age when a number of villages were burned and numerous small villages were aggregated into larger, defensible pueblos. According to LeBlanc, the underlying cause for the intense Late Period warfare was a marked deterioration of the climate, leading into the Little Ice Age, when the climate worldwide became colder and drier, causing loss of agricultural potential. The climatic change was so dramatic that farming was discontinued over much of the Southwest. The scarcity of resources encouraged warfare among the ancestral Puebloans as well as defensive site locations and architecture and the establishment of more inclusive core communities. The fourteenth and fifteenth centuries saw the consolidation of the many communities that had existed earlier into a much smaller number of large pueblos along the Rio Grande, as well as at Acoma, Zuni, and the Hopi mesas. The appearance and development of the kachina cult during the fourteenth century may have helped to cut across kin and ethnic divisions, fostering the cohesion of large communities.

LeBlanc argues that warfare was endemic to ancestral Puebloan society. Despite alternative explanations for any given piece of evidence, multiple lines of evidence all point toward the widespread existence of warfare in the early Southwest. He disputes that the violence was directed against ancestral Apaches or Utes, for the simple reason that the major warfare occurred before these groups arrived in the Southwest. Rather, the wars occurred between different Puebloan groups.

The major Late Period warfare occurred simultaneously at a number of sites throughout the region, at a time when the world climate was changing for the worse, which strengthens LeBlanc's case for what he calls a "scarce resources/carrying capacity model" for the origin of war. In his view, such other motives as revenge or warrior prestige are secondary, happening after earlier wars over resources. Influenced by Lawrence Keeley's War before Civilization (1996), he points out that people lived as hunter-gatherers during most of the million years of human history. During human evolution, war did not involve large, formal battles but raiding and ambush. This form of violence, with many small-scale attacks, over time led to enormous population loss in hunter-gatherer societies.

After considering the genetic basis for human violence, LeBlanc points out that we are not only hard-wired to fight but also genetically inclined to avoid battle if it is not necessary. He cites historical cases where long-established enemies quickly became peaceful when conditions of agriculture, trade, technology, and security improved. He believes that we currently live in a world where it is possible to avoid scarcity of resources. Hence there is cause for a guarded optimism about peace in our future.

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STEVEN LEBLANC is an archaeologist who is currently the director of collections at the Peabody Museum of Archaeology and Ethnology at Harvard University. His fieldwork in the Mimbres area of New Mexico resulted in such publications as The Mimbres People (1983) and The Galaz Ruin (with Roger Anyon, 1984). Investigations in the El Morro/Zuni region in the 1970s led him to reconsider the role of warfare in ancient cultures. He has published numerous articles on prehistoric war and co-edited Deadly Landscapes (2001), a set of case studies concerning warfare in the Southwest. The interview was conducted by telephone between Santa Fe, New Mexico, and Cambridge, Massachusetts, on June 10, 2011. We focused on LeBlanc's books Prehistoric Warfare in the American Southwest (1999) and Constant Battles (with Katherine Register, 2003).

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DJL (Deborah and Jon Lawrence): In Prehistoric Warfare in the American Southwest, you give overwhelming evidence for the existence of extreme violence in a region and during a time that many have thought to be peaceful. Puebloans have long been regarded by the general public as having an idyllic lifestyle. Before your book, many archaeologists and anthropologists had ignored the possibility of such violence. How did such perceptions come about? Has opposition to your perspective in the archaeological community lessened since the publication of your book in 1999? We recently heard Doug Schwartz talk about Arroyo Hondo, and he seemed to be quite in tune with your views, so we suspect that there has been some change.

SL (Steven LeBlanc): In the literature from the late 1800s and early 1900s, archaeologists and others were much more willing to see sites as defensive than they were in 1970, so there certainly was a change in attitude over the years from a willingness to recognize warfare to one of almost complete rejection of it. But I don't really know the reasons for such perception changes, and I haven't pursued that line of inquiry. My concern is to figure out what was really going on in the prehistoric Southwest, based on the archaeological evidence.

After reading Prehistoric Warfare in the American Southwest, a number of scholars, both inside and outside the Southwest, reconsidered their own data. Indeed, Doug Schwartz has said that when he began to think about Arroyo Hondo in the terms that I had put forth, he reevaluated the evidence and now thinks that much more warfare occurred there than he originally thought.

In the book Deadly Landscapes that I jointly edited with Glen Rice, there is a chapter by David Tuggle and J. Jefferson Reid that lays out the case for warfare at Grasshopper Pueblo. I had no idea that so much coherent and dramatic evidence existed for warfare there, even though I had read most of the literature about the site. But when they pulled it all together, I said, "Oh my goodness!"

I think that the neglect of warfare in the archaeological community arises not only from not particularly wanting to think about it but also from not having a good framework to think about it. Also, by the time you have dug through and worked on a site for years, you begin to have considerable empathy for the people who lived there. You realize how hard their lives would have been and how clever they would have had to have been to survive. It is a natural human reaction not to want to see those we empathize with as being warlike.

DJL: Schwartz talked about one of the last groups that joined the Arroyo Hondo pueblo. The people showed evidence for rickets in their skeletal remains. They must have been relatively easy prey for enemies. It was incredibly sad to hear about these people who were barely surviving and who had such terrible diseases.

SL: Yes! When people all over the Southwest moved into large defensive sites in the late 1200s and 1300s, it really hurt their diet. One reason was that the women could no longer go out and forage because the presence of enemies made it too dangerous. So a lot of the wild plants that they would have collected and that would have supplemented and increased the variety of the diet were not available. They may still have had some corn, but their diet had definitely declined in breadth. You can also see that in the children's skeletal remains.

Intense warfare had a major impact on people's lifestyles all over the world. The level of warfare in other parts of North and South America and in parts of the Old World was much more severe and had much more of an impact on people's lives than many people realize. If you come to the study of the Southwest with a broad misconception about the past, then it's easy to extend that misconception into your view of the Southwest.

DJL: Other archaeologists come to different conclusions concerning the evidence that you give for war — defensive site locations, clustering and ultimate agglomeration of sites into large architectural units, burning of sites, unburied bodies, and so forth. During the discussion that followed a recent talk in Santa Fe by E. Charles Adams, the following ideas were brought forward: that Homolovi was repeatedly abandoned when the weather became too arid for farming; that the people moved up onto the Hopi mesas but came back down again when the weather improved; that the sites may have been burned by the occupants to prevent others from occupying them; that the corn was burned because it was too cumbersome to carry; and that ladder-shaped units were constructed primarily because it was more efficient to build in that manner.

SL: Scientific explanation generally involves independent lines of evidence that all point in the same direction. Any given piece of evidence may have multiple possible explanations, but a series of pieces of evidence that when taken together can be explained naturally in the same way creates a much stronger argument. [Charles] Darwin did not rely on just one piece of evidence to explain evolution. Nobody pointed to only one piece of evidence to explain continental drift in terms of plate tectonics. What is done is to find many different lines of evidence that all show the same pattern and then ask what explanation could account for all of them.

The problem that I have with the arguments about the archaeological evidence for warfare in the Southwest is that they typically involve other possible explanations for merely a single piece of evidence. "There is another possible reason why people were living on hilltops." Or "there is another possible reason why that particular site burned." While those are true statements, they ignore the fact that so many things happened at the same time — the sites were built on a hilltop, the sites were more defensive than they had been previously, they had buffer zones between them, and there is evidence for burning. The idea that all of those things happening at the same time each had a completely different and unrelated explanation is, to me, implausible.

If the people left the Homolovi site because of drought and later came back, that doesn't mean that there wasn't a fear of attack. Whether they left solely because there was a change in climate or because the climate was worse and they feared attack can be very hard to discern. And why would you burn your own corn? It makes no sense at all. Even if you couldn't carry it all away at once, you would go back and make multiple trips until you had it all. The distance between Homolovi and Hopi Mesa, where these people wound up, is only about fifty miles. They moved pottery back and forth between the two places in enormous quantities. If you could move pottery back and forth, you could have carried the corn away. But why not leave it there? What if you were out hunting and a winter storm came on and you had to run into the old ruins for protection? Wouldn't it have been good to have spare corn sitting there? Why would you burn it, unless there were people that you didn't want to take it? If there was no warfare, why would there be people who wanted to do that? The mere fact that you are destroying your property so that no one else can get it means that those people are not your friends.

I also think the idea that spinal ladder construction was the most efficient building method is wrong. A giant massive pueblo, like Grasshopper, is more efficient to build than a ladder-type construction. There are no large plazas at Grasshopper — only very small plazas, so that the building is almost solid with rooms. This is very efficient. The benefit of ladder construction was that they could build very quickly because each individual family was not building its own unit. And when they were done, they had built a defensive external wall in the process. Ladder construction didn't appear randomly throughout the Southwest. It only showed up at times for which there is other evidence for lots of warfare. It was used in the very narrow period for which all of the other evidence for increased warfare shows up.