Social factors predict effects of natural disasters

By Kati Moore

CHICAGO — A society’s response to natural disasters may depend more on social factors than resource accumulation, according to new archaeological studies on ancient societies. The research results, presented by Arizona State University archaeologist Margaret Nelson during a Feb. 16 symposium at the American Association for the Advancement of Science meeting in Chicago, could point to new tools for disaster management.

Nelson and her colleagues used centuries of archeological data, beginning in 600 AD, to study the effects of natural disasters on ancient societies in the American Southwest and North Atlantic islands. They observed that natural disasters such as major droughts or periods of severe cold sometimes caused major social collapse and population declines and other times had almost no effect on the population.

Using empirical data from earlier studies, they developed a set of factors that could contribute to a population’s vulnerability to natural disasters. Populations that had certain risk factors were more likely to experience low food security following a disaster than populations without those risk factors. This connection between risk factors and food security was true in both the American Southwest sites and on the North Atlantic islands. “The pattern is so consistent across the different regions that it can’t be ignored or referred to as just regionally occurring,” Nelson said. Nelson divided the risk factors into two categories: resource factors and social factors. Resource factors included the size and diversity of the population’s food supply. Social factors included the population’s ability to move to new areas and their relationships with groups in other areas.

The researchers found that social factors were much more important than resource factors in predicting food security for populations following natural disasters. “Population resource balance seems to contribute very little to vulnerability to food shortage,” said Nelson. “That was surprising to us.” Groups that were unable to move to new areas or did not have good relations with groups in other areas were much more likely to experience major declines in population or, in some cases, complete social collapse due to food shortages.

Nelson expressed hope that this research can be applied to modern day risk management and disaster preparedness. One challenge, she said, is getting people to think in terms of vulnerability leading up to natural disasters instead of relief and recovery efforts following disasters. Nelson’s ultimate goal for her research, she said, is to “help push forward some better understanding of the way in which we must, must deal with vulnerabilities.”

Kati Moore is a senior at UNC-Chapel Hill majoring in biology with a minor in creative writing. She is Editor-in-Chief of Carolina Scientific, UNC’s undergraduate-run science and research magazine. Follow her on Twitter @KatiJane or read her blog at