A cultural evolutionary model of attribute-dependent norms on behaviors with and without direct payoffs.

Humans are strongly influenced by social norms, including those prescribing different behaviors based on individuals' attributes such as gender. Although such attribute-dependent norms are often inequitable and harmful, the evolutionary mechanisms behind their emergence and persistence remain elusive. Here, we develop a mathematical model of cultural evolution to investigate the dynamics of such norms. Our analysis yields two main findings. First, we show that attribute-dependent norms can evolve through social interactions even when they enforce completely arbitrary behaviors devoid of economic utility (e.g., clothing choices). Second, we find that socioeconomic environments (i.e., payoff structures such as modes of livelihood) influence the initial evolution of norms and leave lasting impacts even after environmental change. These findings provide a formal framework to understand the mechanism behind the emergence and persistence of arbitrary and unequal attribute-dependent norms, offering insights into how we might mitigate their societal harms.