In biological systems, function emerges from interactions among semi-independent components. An example is the brain — a huge society of neurons capable of producing coherent, robust behavior at the whole organism level. Another example is a group of fish that can switch quickly between a loose spatial configuration ideal for foraging to a tight group formation ideal for escaping predators. A theory for how individual components come together to produce functionally useful patterns at the aggregate level remains elusive. 

A first question we might ask is: How collective is the system? Is the system reducible to its parts, or do components come to depend on each other to such an extent that they cannot be considered independently of each other? And, similarly, is a functional pattern at the aggregate level highly sensitive to small changes in components’ behaviors, or is it relatively impervious to perturbations? 

These and similar questions are the focus of a working group, “Quantifying Collective Behavior in Living Systems,” being held at the Santa Fe Institute May 3-5. The working group is organized by ASU-SFI researcher Bryan Daniels, ASU Professor and SFI External Professor Manfred Laubichler, and SFI Professor Jessica Flack. 

“The goal of the working group is to ask whether there are common principles of collective behavior across a diverse set of systems,” said Daniels. “How do groups maintain stable, robust behavior at the aggregate level but stay adaptable such that they can change when the environment requires it? Are there quantitative ways we can measure this across different systems?” 

The hope is that sharing ideas in the working group might allow for a common language for researchers studying collective information processing in multiple disciplines. A mutual area of interest involves finding tipping points — being able to quantify and explain what events cause a system to switch between functional states at the aggregate level or to move from being in exploitative and robust mode to an exploratory and adaptable mode. 

In addition to understanding how fish switch as a group between schooling and foraging, unifying principles of collective behavior might help explain apparently large shifts in political view points in elections or how societies that seem so democratic can suddenly show signs of authoritarianism. 

“How that unfolds is very much the kind of question we’re interested in,” said Daniels. “Maybe the political decision-making process looks similar to how neurons make decisions in the brain or how fish school.” 

Read more about the working group.