We identify a process of global pattern formation that causes regions to differentiate by culture. Violence arises at boundaries between regions that are not sufficiently well defined. We model cultural differentiation as a separation of groups whose members prefer similar neighbors with a characteristic group size at which violence occurs. Application of this model to the area of the former Yugoslavia and to India accurately predicts the locations of reported conflict. This model also points to imposed mixing or boundary clarification as mechanisms for promoting peace.

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Mathematical model predicts ethnic violence

Clear boundaries between groups prevent bloodshed

September 14, 2007

Cambridge, MA—A mathematical model detailed in today's issue of Science can predict the likelihood of ethnic violence in a region by analyzing its ethnic census data. As ethnic violence claims millions of lives around the world, the scientists from The New England Complex Systems Institute (NECSI) who performed the study say the model could help to end these conflicts.

"Science can help by providing a clearer understanding of the impact of policy decisions," says Dr. Yaneer Bar-Yam, president of The New England Complex Systems Institute. "With many factors involved in cultural and ethnic conflict, a model that helps to pinpoint the most critical factors can help to bring bloodshed to an end by allowing us to make interventions that actually work."

According to the study, violence takes place when ethnic groups reach characteristic sizes and population structures.

"Violence normally occurs when a group is large enough to impose cultural norms on public spaces, but not large enough to prevent those norms from being broken," says Dr. May Lim, a researcher on the study currently at the University of the Philippines. "Usually this occurs in places where boundaries between ethnic or cultural groups are unclear."

The model identifies "islands" or "peninsulas" of one population at the characteristic size surrounded by another population as likely areas of violence because boundaries at these sites are unclear. The study suggests that violence can be avoided by identifying these areas and clarifying boundaries before fighting begins.

At the opposite extreme, the scientists say, violence could also be prevented by thoroughly mixing different ethnicities so "islands" and "peninsulas" do not occur. The article in Science does not specify particular policy solutions, but suggests that the insights from this research can guide policy makers to make better decisions.

Though NECSI says the model could be used anywhere, the researchers checked its predictions using data from India and the former nation of Yugoslavia, both of which have suffered ethnic violence. Beginning with the countries' censuses, the model successfully identified key areas of conflict.

"Our research is part of a new area of scientific inquiry, complex systems science. Among other things, this science can mathematically describe how individuals interact to cause collective behaviors," says Dr. Richard Metzler, another researcher on the project currently a consultant in Germany. "The model we used in this research can also be used to understand chemicals interacting in a test tube that separate, like oil and water, and how the boundaries between them behave. This divorces the problem of violence from specific aspects of cultures, to a very general and objective process."

Global Pattern Formation and Ethnic/Cultural Violence appears in the September 14, 2007 issue of Science.