In this paper, a model of community formation and organizational complexity is presented, focusing on the fundamental role of social interactions and information transmission for the development of complex social organisation. The model combines several approaches in complex systems thinking which has garnered increasing attention in archaeology. It is then outlined how this conceptual model can be applied in archaeology. In the absence of direct observations of constituent social interactions, archaeologists study the past through material remnants found in the archaeological record. People used their material surroundings to shape, structure and guide social interactions and practices in various ways. The presented framework shows how dynamics of social organisation and community formation can be inferred from these material remains. The model is applied on a case study of two communities, Sagalassos and Düzen Tepe, located in southwestern Anatolia during late Achaemenid to middle Hellenistic times (fifth to second centuries BCE). It is suggested that constituent interactions and practices can be linked to the markedly different forms of organizational structures and material surroundings attested in both communities. The case study illustrates how the presented model can help understand trajectories of socio-political structures and organizational complexity on a community level.