The social cost of partisanship

Implementing policies that bring an overall social benefit can be quite difficult due to the myriad of ways in which different individuals and groups may be impacted, and the variety of targets, beliefs and agendas the policy-makers themselves may have. Examples include the implementation of measures with the objective of reducing carbon dioxide emissions and the implementation of guidelines for conducting stem cell research. Here, we use an agent-based modeling approach to investigate the effects of conservatism and partisanship on the efficiency with which large populations reach consensus on the ``correct'' decision. Remarkably, we find that conservative agents do not destroy the groups' ability to reach consensus. In fact, conservatives enable the system to maintain high efficiency, even in the presence of large levels of noise. In contrast, we find that even a small number of partisans results in low efficiency, especially for large levels of noise. We conclude that while conservatism improves social outcomes, partisanship can have significant social costs.