Towards the unification of the behavioural sciences Professor Herbert Gintis (New Mexico, USA / Budapest, Hungary) Summary: Despite their distinct objects of study, the human behavioural sciences all include models of individual human behaviour. Unity in the behavioural sciences requires that there be a common underlying model of individual human behaviour, specialized and enriched to meet the particular needs of each discipline. Such unity does not exist, and cannot be easily attained, because the various disciplines have incompatible models and disparate research methodologies. Yet, recent theoretical and empirical developments have created the conditions for unity in the behavioural sciences, incorporating core principles from all fields, and based upon theoretical tools that transcend disciplinary boundaries. This presentation sketches a set of principles aimed at fostering such a unity. They include: (1) geneculture co-evolution as a unifying dynamical tool; (2) evolutionary and behavioural game theory as transdisciplinary lexicons for communication and model-building; (3) the rational actor model, rooted in evolutionary biology but developed in economic theory, applied to all the human behavioural disciplines; and (4) the treatment of strategic dynamical systems as complex adaptive systems with emergent properties.