Embedded in current research on determinants of health-related behaviours, this thesis develops an agentbased model to further explore and explain the links between living environment and physical activity in adolescents. Challenging the theoretical and empirical basis of the socio-ecological model that underpins most of current studies, this work leads to a relational conceptual framework that integrates social positions and dispositions with daily mobility and physical activity in both a spatial and temporal perspective. Three increasingly complex agent-based models are developped on this unusual framework that does not explicitly include interactions. Although further investigation is required to fully understand the properties of the models, the study highlights the benefits of this modelling approach that identifies new ways of thinking andanalytical opportunities and gives feedback on the data used.
