Insect societies are the leading examples of collective cognition by social groups. Much like a single animal, a colony of ants can evaluate its surroundings, process information, and make decisions. Cognition emerges from a network of interacting ants, just as individual cognition emerges from interactions among neurons in the brain. The special appeal of these societies is that their parts-individual insects-are themselves complex cognitive entities, providing a unique opportunity to study the interplay between information processing at these two levels. In this talk I will show how individual behavioral rules and communication networks allow many poorly informed ants to make effective collective decisions. I will further show how colonies amplify the limited cognitive capacity of single ants and how they evade certain irrational consequences of individual choice. Finally, I will consider the limits of collective cognition by exploring when it can improve performance by integrating multiple agents, and when it can instead lead to harmful information cascades.

Stephen C. Pratt received a Ph.D. in neurobiology and behavior from Cornell University, Ithaca, NY, in 1997. Since then, he has worked at Harvard University, the Massachusetts Institute of Technology, Princeton University, and the University of Bath, U.K. He is currently an Associate Professor in the School of Life Sciences at Arizona State University,Tempe, AZ. His research focuses on the emergence of complex social behavior in leaderless and decentralized animal groups, particularly social insects. He employs both theoretical and empirical approaches, and is also active in the development of bio-inspired algorithms for swarm robotics applications.

Christophe Chamley received an MA in Mathematics at the University of Strasbourg (France) and PhD in economics at Harvard University. He is professor of economics at Boston University and director of studies at the EHESS (Paris). He is a fellow of the Econometric Society. He held visiting positions at Harvard University, MIT, Stanford University, University of Bonn, University Carlos III in Madrid, and University of Louvain. He published in all top journals in economics on the theory of optimal taxation and the public debt, history of public finances, monetary policy, economic fluctuations, social learning. He is the author of Rational Herds: Economic Models of Social Learning at Cambridge University Press.