ABSTRACT
Since the Middle Pleistocene, human cultures have become increasingly varied in terms of regional traditions and traits of social function. While behavioural norms and conventions are subject to emulation and reproduction, they are based on interactions restricted to a limited set of peers.
This chapter introduces readers to social interactions in simple regular networks. Social structure tends to generate much more diverse and intricate results than mathematical models which rely on random pairwise matching. This chapter offers a perspective antithetical to that of Chapter 4, and illustrates that localised interactions can give rise to both universal and local institutional setups. The former institutions may be subject to phase transitions while the latter create sophisticated patterns of local rules that resemble fractal structures. This chapter further shows that in localised interactions, populations are more able to establish socially efficient conventions but can also sustain behavioural rules that do not emerge in more global types of interactions.
Some of the concepts discussed are: von Neumann and Moore neighbourhoods, risk and Pareto dominance, phase transitions, the voter model, and co-evolving networks.
