While the engineering of digital twins (DTs) of cyber-physical systems already faces a number of challenges, DTs of socio-technical systems are made even more complex by human and social factors, and a comprehensive representation of their internal relations is currently lacking. DTs for socio-technical systems could open up new ways of achieving common societal goals by i) providing an understanding of complex interactions and processes, and by ii) facilitating the design of and participation in collective actions. In this context, dynamic adaptation and motivational strategies would be required to swiftly address sub-optimal system behavior. To enable the model-driven engineering of DTs responding to such requirements, we propose a conceptual model of socio-technical systems and discuss it with use-case scenarios. The presented approach supports our vision of future DT-based model-driven interventions, empowering citizens and stakeholders in driving societal change and increasing community resilience.