Trust, Communication, and Inequality

Inequality in wealth is a pressing concern in many contemporary societies, where it has been show to co-occur with political polarization and policy volatility, however its causes are unclear. Here we demonstrate in a simple model where social behavior spreads through learning that inequality can covary reliably with other cooperative behavior, despite a lack of exogenous cause or deliberate coordination. In the context of simulated cultural evolution selecting for trust and cooperative exchange, we find both cooperation and inequality to be more prevalent in contexts where the same agents play both the roles of the trusting investor and the trusted investee, in contrast to the condition where these roles are divided between disjoint populations. Cooperation is more likely in contexts of high transparency about potential partners and with a high amount of partner choice; while inequality is more likely with high information but no choice in partners for those that want to invest. While not yet a full model of contemporary society, our approach holds promise for examining the causality and social contexts underlying shifts in income inequality.