Independence and interdependence in collective decision making: an agent-based model of nest-site choice by honeybee swarms

Abstract

Condorcet's jury theorem shows that when the members of a group have noisy but independent information about what is best for the group as a whole, majority decisions tend to outperform dictatorial ones. When voting is supplemented by communication, however, the resulting interdependencies between decision makers can strengthen or undermine this effect: they can facilitate information pooling, but also amplify errors. We consider an intriguing non-human case of independent information pooling combined with communication: the case of nest-site choice by honeybee (Apis mellifera) swarms. It is empirically well documented that when there are different nest sites that vary in quality, the bees usually choose the best one. We develop a new agent-based model of the bees' decision process and show that its remarkable reliability stems from a particular interplay of independence and interdependence between the bees.

Independence and interdependence in the nest-site choice by honeybee swarms: Agent-based models, analytical approaches and pattern formation

“…Independence and interdependence in the nest-site choice by honeybee swarms: agent-based models, analytical approaches and pattern formation In a recent paper List, Elsholtz and Seeley [List et al 2009] have devised an agent-based model of the the nest-choice dynamics in swarms of honeybees, and have concluded that both interdependence and independence are needed for the bees to reach a consensus on the best nest site. We here present a simplified version of the model which can be treated analytically with the tools of statistical physics and which largely has the same features as the original dynamics.…”

“…These rates of finding the different nests will be taken to fulfill k α=1 π α < 1, and we will set π 0 = 1 − k α=1 π α . Throughout this paper we will follow [List et al 2009] and assume that the π α , α = 1, . .…”

“…In a recent paper [List et al 2009] List, Elsholtz and Seeley (LES for short from now on) presented an agent-based model of the decision making processes in the nest-site choice of honeybee swarms, and their paper has attracted a significant amount of attention in the public media (see e.g. The Economist of 13 February 2009).…”

“…The main aim of this current paper is to present the modified version of LES's model, and to show how it can be addressed with the tools of statistical physics. In the second part of our work we then extend the model of [List et al 2009] to include space, and study the pattern formation dynamics of this extended model.…”

“…The natural process modeled by LES is the following: once a year once a colony of bees has reached a certain size, a 'search committee' consisting of several hundred bees swarm out to identify suitable nest sites, and once an agreement has been reached the original colony divides, and the queen leaves with about two thirds of the bees for the new nest (see [List et al 2009] and references therein). The process LES are interested in is the actual decision making.…”