Agent-based models and individualism: is the world agent-based?

Agent-based models (ABM) are an increasingly popular tool in the social sciences. This trend seems likely to continue, so that they will become widely used in geography and urban and regional planning. We present an overview of examples of these models in the life sciences, economics, planning, sociology, and archaeology. We conclude that agent-based models strongly tend towards an individualist view of the social world. This point is reinforced by closer consideration of particular examples. This discussion pays attention to the inadequacy of an individualist model of society with reference to debates in social theory. We argue that because models are closed representations of an open world it is important that institutions and other social structures be explicitly included, or that their omission be explained. A tentative explanation for the bias of agent-based models is offered, based on an examination of early research in Artificial Intelligence (AI) and Distributed Artificial Intelligence (DAI) from which disciplines the approach is derived. Some implications of these findings are discussed. We indicate some useful research directions which are beginning to tackle the individualism issue directly. We further note that agent-based models’ underlying assumptions are often hidden in the implementation details. We conclude that such models must be subject to critical examination of their assumptions, and that model builders should engage with social theory if the approach is to realise its full potential. “BRIAN: Look. You've got it all wrong. You don't need to follow me. You don't need to follow anybody! You've got to think for yourselves. You're all individuals! FOLLOWERS: Yes, we're all individuals! BRIAN: You're all different! FOLLOWERS: Yes, we are all different!