Chapter 16 Cultural-historical Activity Theory Meets Developmental Systems Perspective: Transformative Activist Stance and Natureculture Anna Stetsenko Abstract. Recent developments in the interdisciplinary field of research on human development, amounting to no less than a conceptual revolution, strongly suggest that the so-called interactionist consensus on nature-culture debates falls far short of accounting for the true complexity of developmental dynamics. There is a strong affinity on this point between the recently influential developmental systems perspective (DSP) and Vygotsky’s works including in its activity theory lineage. In these frameworks, individual and environmental characteristics are understood to continuously emerge in the life course while codefining and cogenerating each other in the very process of developmental transactions. Both frameworks shift beyond the concept of development as a mechanically additive, hybrid product in which external and internal (genetic and environmental) influences are mechanically summated and combined as extraneous and separate units to be added to each other. Furthermore, while sharing the emphasis on joint determination by multiple causes, contextual sensitivity and contingency, Vygotsky’s framework expanded through Transformative Activist Stance is more radical and resolute in offering conceptual tools to understand development as an activity-dependent, emergent co-construction of developmental outcomes by human beings co- acting with others in agentively co-authoring their communal world while relying on available cultural resources. This discussion creates context in which the relevance of works by Mariane Hedeggard can be highlighted. Keywords Agency Developmental Activist Biological ----------- Published as Stetsenko, A. (2019). Cultural-historical activity theory meets developmental systems perspective: Transformative activist stance and natureculture. In A. Edwards, M. Fleer and L. Bottcher (Eds.), Cultural-historical approaches to studying learning and development: societal, institutional and personal perspectives (pp. 249-262). London: Routledge. Page 249