Modelling Behavioural Systems: Integrating Psychology and Complex Systems Science

Abstract

In order to rise to the challenge of modelling the behavioural systems with which population-scale behavioural science is concerned, we must make Isaac Asimov’s concept of psychohistory less science fiction and more science fact. To do this, we need to integrate complex systems science and psychology in order to place individual behavioural response functions in relation to one another. We seek to do this in the present work, and so draw on complex systems science to provide a network representation of social systems before turning to Kurt Lewin’s gestalt psychology to provide a model of individual behaviour within those systems. We extend Lewin’s model to a probabilistic variant that can be reduced by grounding it in neuropsychological perspectives on the mind. This allows us to model behaviour as the outcome of the interaction between personal psychological and environmental characteristics that create driving and restraining forces that influence a behavioural likelihood distribution. This behavioural likelihood distribution, we show, can be changed more sustainably by the reduction of restraining forces through changes either to the environment or to the structure of the mind itself. We then integrate our complex systems science and psychology perspectives into a model of behavioural systems as self-organising systems subject to diffusion through their social networks and derive an equation that describes these system dynamics. This work is necessarily primarily theoretical, but it is necessary only in the context of the objective of developing an empirical methodology that can identify, attribute and forecast change in behavioural systems. We conclude with a consideration of how this research program might be advanced.