# The Emergence of Consensus: A Primer

## TL;DR

This paper reviews how social consensus emerges spontaneously in populations, exploring mechanisms, network effects, and experimental insights from game theory, evolutionary science, and complex systems.

## Contribution

It provides a compact overview of the main theories, models, and experimental findings on spontaneous social consensus formation across disciplines.

## Key findings

- Consensus can emerge without central authority
- Social networks influence the speed and stability of consensus
- Experimental results highlight key mechanisms of behavioral contagion

## Abstract

The origin of population-scale coordination has puzzled philosophers and scientists for centuries. Recently, game theory, evolutionary approaches and complex systems science have provided quantitative insights on the mechanisms of social consensus. However, the literature is vast and widely scattered across fields, making it hard for the single researcher to navigate it. This short review aims to provide a compact overview of the main dimensions over which the debate has unfolded and to discuss some representative examples. It focuses on those situations in which consensus emerges 'spontaneously' in absence of centralised institutions and covers topic that include the macroscopic consequences of the different microscopic rules of behavioural contagion, the role of social networks, and the mechanisms that prevent the formation of a consensus or alter it after it has emerged. Special attention is devoted to the recent wave of experiments on the emergence of consensus in social systems.