Topics of Interest

Emergent Spatial Structures in Flocking Models: A Dynamical System Insight

Jean-Baptiste Caussin, Alexandre Solon, Anton Peshkov, Hugues Chaté, Thierry Dauxois, Julien Tailleur, Vincenzo Vitelli, and Denis Bartolo

Published April  8, 2014

How do individual animals form swarms, schools, and flocks? In the 1990s, physicists modeled collections of self-propelled particles (so-called “active matter”) and could simulate the ordering that occurs in animal flocks.  Theoretical models have reproduced many aspects of this collective behavior, but a number of questions have persisted. One concerns the observation that in polar, active matter—think of a collection of small, mutually interacting swimming arrows—the particles organize themselves into three possible pattern classes: density waves, solitary waves (solitons), and traveling “droplets.” Read more.


Controlling Self-Organizing Dynamics on Networks Using Models that Self-Organize

Pierre-Andre' Noel, Charles D. Brummitt, and Raissa M. D’Souza

University of California, Davis, California 95616, USA


Controlling self-organizing systems is challenging because the system responds to the controller. Here, we develop a model that captures the essential self-organizing mechanisms of Bak-Tang-Wiesenfeld (BTW) sandpiles on networks, a self-organized critical (SOC) system. This model enables studying a simple control scheme... read more.

DOI: 10.1103/PhysRevLett.111.078701

The Diffusion of Microfinance 

Abhijit Banerjee, Arun G. Chandrasekhar, Esther Duflo, and Matthew O. Jackson

Science 26 July 2013: Vol. 341 no. 6144 DOI: 10.1126/science.1236498

How do the network positions of the first individuals in a society to receive information about a new product affect its eventual diffusion? To answer  this question, we develop a model of information diffusion through a social network that discriminates between information passing (individuals must be aware of the product before they can adopt it, and they can learn from their friends) and endorsement (the decisions of informed individuals to adopt the product might be influenced by their friends’ decisions). We apply it to the diffusion of microfinance loans ... read more.


Anticipating Critical Transitions

Article by: Scheffer et al. (2012)


Tipping points in complex systems may imply risks of unwanted collapse, but also opportunities for positive change. Our capacity to navigate such risks and opportunities can be boosted by combining emerging insights from two unconnected fields of research. One line of work is revealing fundamental architectural features that may cause ecological networks, financial markets, and other complex systems to have tipping points. Another field of research is uncovering generic empirical indicators of the proximity to such critical thresholds. Although sudden shifts in complex systems will inevitably continue to surprise us, work at the crossroads of these emerging fields offers new approaches for anticipating critical transitions.


Scheffer et al. (2012). Anticipating Critical Transitions. Science 338, 344-348.

Also, see related IRCS Interpretive Brief

Leads on Predicting Institutional Collapse

James K. Hazy

A recent study uses catastrophe models, an approach that has been proven across multiple disciplines from physics to ecology, to describe tipping-point events in dynamical systems. These are points, or values of a parameter--describing environmental conditions, the "container," wherein the system functions--that once crossed, can lead to sudden collapse in population density. If similar models can be applied to human organizing, then lessons from these systems may also apply to potential catastrophic collapse of social, political, and economic systems.

The study was conducted using yeast cultures, and therefore is not directly applicable in the human case. But it does provide possible leads for human systems researchers... read more.

The Social Conquest of Earth

a book by E. O. Wilson

The evolutionary basis for pro-social behavior in humans remains a controversial topic. In particular, the question of how large-scale human cooperative activities like social, cultural, political and economic systems might have evolved through natural selection processes is a fundamental one. Of particular interest is the appropriate unit of selection for individual and collective altruistic and pro-social behavior because these behaviors enable complex organizing.

Interestingly, this question is also at the center of a theoretical dispute in evolutionary biology that erupted as a consequence of the cover article in the journal Nature written by a group that included the prominent evolutionary biologist Edward O. Wilson. The dialogue continues with Wilson's new book: The Social Conquest of Earth.... read more.

Decision-Making in Kind and Wicked Environments

James K. Hazy

Deciding which expert to believe when one is decidedly more confident that others is both a common practical problem and an important conundrum in the theory of human interaction dynamics (HID). As shown in a recent study, it turns out that the best choice depends upon how well consensus opinion correlates with conditions in the environment ... read more.

Location and Neighborhood Factors are Powerful Attractors Driving Social Functioning

Washington, DC

Over the course of 40 years, Robert J. Sampson has been gathering massive amounts of sociological data about the USA's city of Chicago's neighborhoods. His study, published in his recent book, Great American City: Chicago and the Enduring Neighborhood Effect, challenges current orthodoxy and offers strong support for complex systems methods. Among other things he found that two coarse-grained social system properties drove neighborhood outcomes more 


Mark your calendars...

The Institute sponsors several events that are intended to further research in Human Interaction Dynamics( HID). For example, it is sponsoring a symposium in Buena Vista, Florida  ... read more 

The Institute

The Institute for Research in Complexity and Society applies findings and insights from the scientific and mathematical study of complex systems to the challenges and opportunities facing today's world community ... read more