Eur. Phys. J. B 67, 369-375 (2009)
https://doi.org/10.1140/epjb/e2008-00406-4

Micro-bias and macro-performance^*

¹ Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
² Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL, 60208, USA
³ Departamento de Física, Universidade Federal do Ceará, 6030 Ceará, Brazil
⁴ Northwestern University Clinical and Translational Sciences Institute, Chicago, IL, 60611, USA
⁵ Managerial Economics and Decision Sciences, Kellogg School of Management, Northwestern University, Evanston, IL, 60208, USA

Corresponding authors: ^a msales@northwestern.edu - ^b amaral@northwestern.edu

Received: 1 August 2008
Published online: 5 November 2008

Abstract

We use agent-based modeling to investigate the effect of conservatism and partisanship on the efficiency with which large populations solve the density classification task – a paradigmatic problem for information aggregation and consensus building. We find that conservative agents enhance the populations' ability to efficiently solve the density classification task despite large levels of noise in the system. In contrast, we find that the presence of even a small fraction of partisans holding the minority position will result in deadlock or a consensus on an incorrect answer. Our results provide a possible explanation for the emergence of conservatism and suggest that even low levels of partisanship can lead to significant social costs.