Resource stress and subsistence diversification across societies

While climate change is accelerating, its consequences are not entirely new. Many societies in the ethnographic or anthropological record have experienced climate instability, natural hazards and resource shortages in their histories. Examining indigenous practices may help suggest practical sustainable solutions for food insecurity in response to climate change. Two bodies of research have suggested that subsistence diversification may increase sustainability. International development experts today commonly recommend diversification for subsistence economies. Ecological scientists suggest that generalist species adapt better to unpredictable environmental events, whereas specialists adapt better to more stable environments. We assume that societies that survive to be recorded in the ethnographic record exhibit ecologically relevant cultural adaptations and test whether subsistence diversification is more likely in societies experiencing climate unpredictability and more resource stress. We use a worldwide and cross-cultural sample of 91 societies. We find that chronic scarcity and climate instability both predicted more subsistence diversity, controlling for intra-annual temperature variability, subsistence strategy and phylogeny. Other resource stressors, such as natural hazards and famine, are not predictive. Thus, our results provide partial support for the idea that subsistence diversity provides resilience to societies facing heightened environmental unpredictability and resource stress.