Normative Infrastructure Supports Within-Group Adaptation Among the Turkana

Abstract

A distinguishing feature of humans is our ability to create rules that support social order and modify existing rules when conditions change. Cultural evolution leads to more rapid change in the human environment compared to genetic evolution, suggesting that the need to adapt norms would have been a constant pressure on human societies. The main theory in cultural evolution for how group-beneficial change in norms can happen is cultural group selection: competition between groups that have different norms and institutions leads preferentially to the spread of norms and institutions that increase the success of the cultural group. But cultural group selection cannot explain rapid changes in norms within groups, as it can operate only on existing variation among groups. We posit that over millennia cultural group selection acted not just on norms, but crucially also on normative infrastructure – the meta-norms that structure a group’s processes for classifying and enforcing norms, favoring infrastructures with combinations of stability and innovativeness that aid the success of the cultural group. We conducted vignette experiments to elicit the normative infrastructure of the Turkana, a pastoral society in Kenya in which social order is maintained informally. We present results from 202 subjects, which can help to assess how Turkana normative infrastructure resembles or differs from legal order, a broad class of solutions that permit rapid innovation without loss in stability.