Margaret Nelson, archaeologist

Drawing on her decades of unearthing ancient societies, this researcher aims to awaken us to our own frailties. Interview by Molly Sharlach

March 28, 2014

Margaret Nelson on the Rio Grande in southwestern New Mexico, the eastern margin of the Mimbres Region. Photo: Steve Northup

Popular writings on the prehistory of the American Southwest often describe the “disappearance” of people from sites such as Mesa Verde in the 1200s. People, of course, do not just disappear. But societies do collapse. “It’s painful, and we don’t want to experience that,” says Margaret Nelson, a professor of anthropology at Arizona State University. She has studied the Mimbres society of southwestern New Mexico for the last 30 years, and she believes contemporary societies have much to learn from the Mimbres’ demise.

Nelson headed an interdisciplinary research team, the Long-Term Vulnerability and Transformation Project (LTVTP). In 2011, the group published a paper in the journal Ecology and Society on water management strategies and adaptations over a period of 700 years in three prehistoric societies: the Mimbres, the Zuni in northern New Mexico and the Hohokam in central Arizona. Each group took a different approach to irrigating crops—mainly maize, the base of their diets. All experienced a profound drought in the 1100s. The outcomes, the team found, varied dramatically.

More recently, Nelson helped start a collaboration with members of the North Atlantic Biocultural Organization, who study Norse settlements in Iceland and Greenland. The team has developed a framework for cross-case comparisons of weaknesses and responses to food shortages. The work reveals a strikingly consistent pattern: When the going gets tough, those with inflexible survival strategies never fail to fall. And social factors often play as large a role as environmental ones.

Nelson discussed the flaws of these ancient societies, and what they mean for modern disaster management, during a symposium at the February 2014 meeting of the American Association for the Advancement of Science in Chicago. SciCom’s Molly Sharlach sat down with Nelson to find out more about what we can learn from the mistakes of our forebears.

Why do you study archaeology?

I got interested in archaeology in college when I started doing fieldwork. I’ve loved it ever since. I’m 62 now, so that’s a long time. I think you have to love whatever you study, because doing research is hard work. And then you have to think it makes a difference. When I was younger, I was trying to make a difference in my field, trying to contribute to method and theory. But now I’m seeing that a long-term perspective can make a huge difference in the way people see contemporary problems, and the potential for different ways to solve those problems.

How did that transition come about?

As I did more work on environment and climate, I began to see people trying to solve problems in ways that I was convinced could be improved by understanding long-term archaeological and historical sequences. For example, I heard a talk show on NPR about a new book, whose author proposed that we should move toward homogenizing culture to improve global communication. I was appalled that somebody would think that was a good idea. I know that time and time again, as people created boundaries around themselves or homogenized, when they had a crash, they had a very bad crash. There weren’t as many options available to solve their problems. If everybody thinks the same, you limit the range of possible solutions. So an archaeological perspective on that challenge would say it’s a very bad idea.

What’s an example of past cultural conformity that led to an inability to solve problems?

Social change is really complicated. It isn’t just the conformity that contributes to the problem. It’s that conformity creates a lot of vulnerability, because you limit your ability to solve problems.

We look at symbols in pottery for some idea of what people’s traditions are. In the Mimbres area, from about A.D. 1000 to 1130, people were highly conforming in the way they expressed their social relationships. It wasn’t the conformity that led to their collapse. It was the conformity that created vulnerability, and there was such a big collapse that all Mimbres villages were depopulated. They stopped making their beautiful pottery. Their traditions just ceased. That’s a big institutional collapse. But people didn’t disappear, as some popular writings suggest.

When you conform, you make yourself vulnerable to any problems that you need a diversity of perspectives to solve. In the Mimbres, people didn’t have any external relationships, either. They bounded themselves, ignoring people to the west and north, and keeping a separate identity. It reminds me a little bit of some nation-states now, and that’s dangerous. Sometimes you have to do that, but you also have to recognize that you’re creating vulnerability.

"As people created boundaries around themselves or homogenized, when they had a crash, they had a very bad crash."

Do we know what led to that collapse?

One factor was a lengthy dry period right around 1130. We also know that there was no hierarchy of decision-making. In our society, we have hierarchies everywhere, and leaders make decisions. Making decisions and adjusting to things is slower when there’s no hierarchy.

People had also depleted some of their river resources and cut away the riparian zones for fields. They had depleted some of their large game. And then they had the longest, driest period they’d had in over 400 years. So it wasn’t just the climate. It wasn’t just the conformity. It wasn’t just the resource depletion. A constellation of factors contributed to that collapse.

How did you come up with the idea of comparing responses to climate change in the American Southwest and the North Atlantic?

I was invited to a conference in Maine to present research on the rigidities of human societies that get them into trouble, especially when there are climate shocks. I met some people there who work in the North Atlantic, and we realized we do the same thing. They look at the Norse; we look at traditional indigenous people. They’re on polar islands; we’re in the deserts of the Southwest. The centuries are the same, but that doesn’t really matter, because the climate impacts are so different.

A National Science Foundation program officer at the conference encouraged us to apply for funding. If we could make arguments about impacts and adjustments to climate change that transcended these two incredibly different regions, then people couldn’t disregard them as being local or regional conclusions.

The first challenge was to get everybody to agree on a method to estimate climate shocks. Then we went to the archaeological and historical records from the different regions, and asked, what are the key variables that create vulnerability to food shortage? We ended up agreeing on eight variables that are really important. Some of them are: Was there adequate food on the landscape? Did people deplete any resources? Did they have a diversity of resources? If the diversity is low, then they’re vulnerable. And so on. Then there are social variables: Could people have moved away from the problem? And as you attach numbers to that, the next person who works in the Zuni region of the northern Southwest has to quantify it in the same way.

We’re able to see a very consistent relationship between the amount of vulnerability to food shortage you have before a shock and the impact of the shock. It’s just what you’d expect. I think any disaster manager would say, okay, we knew that. But disaster management practice is more often focused on recovery—not because disaster managers want it that way, but that’s the funding they can get. You wait until things crash down, and then you fix them.

In societies with lower vulnerability, you don’t even notice the climate shock in the archaeological record. Everything just goes on as normal 

What are the plans to apply this knowledge to contemporary societies?

The first step is to get the information out there. A couple of years ago, I gave a talk in Taiwan about tradeoffs—whenever we solve a problem, we create a new vulnerability. We see it in the archaeological record of the Southwest when we look at how people have solved the problem of variable precipitation through irrigation systems.

The director of research for the whole of Taiwan was at the meeting, and his most recent responsibility was to create a sustainability plan for Taiwan. He came up to me and said, “You’ve ruined my life. I had a simple plan. We were going to recycle more, we were going to do X and Y and Z, and in none of those cases did I think about what vulnerabilities I was creating by those decisions. And now I have to.”

Well, fantastic. I don’t expect to be at the table, though I think it would be great if archaeologists were at the table. I think contemporary decision-making would be richer, because we do have this long-term experience. Short-term experience is so narrow, and long-term experience is so rich, even if it’s different.

We talked about examples from the past where people made themselves vulnerable, and then their society collapsed. Is there an example where the opposite happened—where people were able to weather the storm better because of the way their society was set up?

One of the best cases comes from the northern part of the Southwest, in the Zuni area. The Zuni people had quite a few different water management systems. With minor changes in climate, they moved from place to place. If we saw that today, we’d call that really inefficient. People are maintaining too many different farming strategies and moving too often—changing their minds. To me, that’s flexibility.

Zuni people still live in the same places they did in the 900s. There’s been depopulation due to disease and all kinds of issues introduced by Europeans, but the Zuni are still there. If an engineer or an economist looked at the Zuni and the Hohokam, they would say, “These people in the Hohokam area, they really know what they’re doing. They built the biggest irrigation system in all of North America. They are organized.”

And they fell so hard, because they became so vulnerable. There’s no reason why you can’t build a big irrigation system and keep your vulnerabilities low. If they had maintained a lot of strategies that might look kind of inefficient, perhaps they wouldn’t have collapsed—at least not as hard as they did. To me, that’s the lesson.


© 2014 Molly Sharlach

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