Collective outcomes emerge from the interactions among variable agents. In many social groups, including ant colonies and human cities, individuals vary in interaction frequency. Furthermore, per capita energy cost, an index of collective performance, decreases as group size increases.
In this project we explore the original hypothesis that interaction frequency and group energetics are both a manifestation of nontrivial collective behavior. Specifically, we assert that variation in individual interactions gives rise to nonlinear group energetics, and that there is feedback between the two processes.
We use ants as an empirical model whose social structure can be readily manipulated. We relate changes in network structure to per capita group energetics, and vice versa. Novel image analysis tools provided by our collaborator, Dr. Zhaozheng Yin, are used to collect data on movement and interactions, while state-of-the-art respirometry will measure colony metabolic rate.
In the theoretical effort, Chen and Dr. John Singler try to build mathematical models of the relationship between local interactions and group energetics to explore competition between maximizing information flow across the network and minimizing group energy expenditure.