Fussy groups thwart the collective burden of choice: A theoretical study of house-hunting ants

Abstract

Information is crucial to effective decision making, but too much information can be as detrimental as too little. Pooling information allows group-living organisms to benefit from the ‘wisdom of the crowds’, but could also increase the risk of information overload if not complemented by increased information processing capacity. In this study I use an agent-based model and empirical tests to explore the influence of group-size on information accumulation, and the impact of this on collective decision-making. Larger groups were more effective at sampling the environment in simulations and empirical trials. Simulations suggest this this could render them more susceptible to information overload in candidate-rich environments, in which larger groups suffered delays to decision making because of poorly focussed information sharing. However, the cost of excessive information could be ameliorated if individuals are ‘fussy’ and filter information by withholding information on poor candidates. This may explain observations from empirical trials, in which higher rates of information accumulation in larger groups did not have a clear impact on decision making. These results suggest groups face a potential collective burden of choice from excessive novel information in complex environments. However, collective information-filtering mechanisms analogous to those in the brains of unitary organisms could allow groups to exploit the wisdom of the crowds without suffering from information overload.