The Role of Mutation in Norm Emergence

Mahmoud, S., Griffiths, N., Keppens, J. and Luck, M.

Proceedings of the 5th International Workshop on Normative Multi-Agent Systems. 23-28.

June 2010

Abstract

Norms are a valuable mechanism for establishing co- herent cooperative behaviour in decentralised systems in which no central authority exists. One of the most influential formulations of norm emergence was proposed by Axelrod [1], who defined a model of norms and metanorms that enables norm establishment in popula- tions of self-interested individuals. This paper provides an empirical analysis of aspects of Axelrod’s approach, by exploring some of the key assumptions made in previous evaluations of the model. First, we explore the dynamics of norm emergence and the occurrence of norm collapse when applying the model over extended durations. Second, we investigate in detail the reasons for norm collapse in extended ap- plications of the model and show that both the level of mutation in the population and the precise nature of the reproduction mechanism are significant. Our findings identify characteristics that significantly influence norm establishment using Axelrod’s formulation, but are likely to be of importance for norm establishment more generally.