Abstract for: Towards a Behavioural System Dynamics: Exploring its scope and delineating its promise

We apply the ‘behavioural turn’ to System Dynamics. Humans frequently do not employ strict rationality but make errors and are subject to fallacies. This idea sheds light on the cognitive and human interaction aspects of models and the modelling process. We raise concerns about the current state of ‘Behavioural OR’. To refocus the underlying ideas we return to the Decision Theory roots, take a broader view using the history of science and then review work which first proposed a link to SD. In the core of the paper we explore how behavioural ideas apply to SD. We use the ‘System 1 / System 2’ idea and an existing map of the stages of SD modelling. We then offer a new and detailed framework of the stages of an intervention, indicating the presence of behavioural effects and providing a fine-grained discussion of those effects. We build on this by returning to, and proposing a reconstitution of ‘Behavioural OR’ and so present ‘Behavioural System Dynamics’ (BehSD) in terms of its perspective on phenomena, five new, constitutive axoims, and its potential for improving practice. We reprise the nature and potential of ‘BehSD’ and sketch how research adopting this perspective might go forward.