What Makes a Digital Human Twin More Than a Simulation? A Computational-ecological Stance

The emergence of digital human twins (DHTs) raises questions not only of modeling fidelity but of operational coupling with the environment: the extent to which DHTs can independently perceive, decide, and learn within data-rich virtual environments (VEs). This paper challenges the mirror metaphor: DHTs need not merely reflect their human counterparts but can develop affordance-based perceptions of virtual surround. Building on Object Oriented Ontology (OOO), we treat DHTs as non-human digital objects only partially accessible through their interfaces. Extending affordance theory with Artifact–Artifact Affordance (AAA), we analyze interactions that are not centered on human perception. We present a typology of agent–environment couplings, and propose a conceptual Operational Autonomy Continuum (OAC) for DHTs, arguing for a synergy in which computational methods operationalize ecological (direct) coupling. Drawing on reinforcement-learning principles and law-governed affordance acquisition, we conceptualize how DHTs could transition from passive replicas to partially independent digital agents without exhaustive human programming. The contribution in this paper is conceptual and heuristic, and the example functions as a thought experiment. Our claims concern operational autonomy (means) rather than metaphysical agency (ends or personhood) and are VE-bounded without addressing transfer to physical contexts or questions of rights or moral status.