||The culture of a group represents the characteristics that are commonly shared across members. These characteristics may relate to views, behaviours, social norms or expectations that evolve based on social contagion, with individuals be- ing effectively “programmed” by their social context, on top of their biological disposition. The structure of interactions, and the sources of influence from social links contribute to the cultural polarisation and plurality that feature in groups. In this working paper we introduce and extend a popular model concerning cultural evolution. In particular, we focus on using Social Impact Theory as a means to model the social pressures from sub-groups that lead to the fracture or reinforce- ment of culture within groups.