How does consensus emerge and evolve in complex decentralized social systems? This question engages fields as diverse as sociology, linguistics, cognitive science and network science. Various attempts to solve this puzzle pre-suppose that formal or informal institutions are needed to facilitate a solution. The complex systems approach, by contrast, hypotheses that such institutions are not necessary in order for social consensus to form. In this talk, I will present experimental results that demonstrate the spontaneous creation of universally adopted social conventions. In doing so, I will show how a population's network structure controls the dynamics of norm formation, as captured by the simple Naming Game model. Then, within the same framework, I will discuss how social norms can evolve in the absence of a centralized authority. Finally, I will present some recent results on the modeling of the cryptocurrency market. Adopting an ecological perspective, I will show that the so-called neutral model of evolution reproduces key statistical properties of the market, despite the fact that it assumes no selective advantage of one cryptocurrency over another. These results shed light on the properties of the cryptocurrency market and establish a first formal link between ecological modeling and the study of this growing system.

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References: 

A. Baronchelli “The emergence of consensus: A primer”, Royal Society Open Science 4, 172189 (2018)A. 

El Bahrawy et al "Evolutionary dynamics of the crypto currency market", Royal Society Open Science 4, 172189 (2018) 

D. Centola and A. Baronchelli "The spontaneous emergence of conventions: An experimental study of cultural evolution ", PNAS 112,1989 (2015)