More Than Opinions: The Role of Values in Shaping Fairness and Status in the Ultimatum Game within Structured Societies

Abstract

Asymmetric evolutionary games, such as the Ultimatum Game, provide keys to understanding the emergence of fairness in social species. Building on this framework, we explore the evolution of social value systems and the operational role that social status plays in hierarchically organised societies. Within the asymmetric Ultimatum Game paradigm, where "proposers" suggest terms for resource distribution, and "responders" accept or reject these terms, we examine the assignment of roles between players under a subjective social order. This order is grounded in an emergent status hierarchy based on observable player attributes (such as age and wealth). The underlying rules for constructing such a hierarchy stabilise over time by inheritance and family ties. Despite their subjective nature these (often sub-conscious) value systems have operative meaning in controlling access of individuals to resources and decision making. We demonstrate these effects using a simple but sufficiently complex model with dynamical population size and network structure, where division of resources (prey) is carried out according to the principles of the Ultimatum Game. We focus on the emerging proposer and responder thresholds under distinct social hierarchies and interaction networks and discuss them in relation to the extensive body of Ultimatum Game experiments conducted across a wide range of cultural contexts. We observe the emergence of diverse sharing norms, ranging from unfair to highly generous, alongside the development of various social norms.