Technological complexity and combinatorial invention in small-scale societies

Technology plays a central role in all human societies, from foraging to industrial economies. However, technological solutions come with associated costs, and in small-scale societies, technological complexity reflects this trade-off between efficiency and resource constraints. Here, we analyze this trade-off and show a sublinear scaling relationship between toolkit richness and tool part richness in ethnographic societies. This result indicates diminishing returns where each additional part contributes less to overall toolkit diversity. This scaling holds across diverse ecological and cultural contexts, suggesting a general principle of optimization in tool design. Ethnographic toolkits achieve their adaptability by reusing a core set of versatile parts and selectively incorporating more specialized parts. However, increasing richness also increases complexity, and complexity is costly. We formalize these dynamics within a combinatorial optimization framework and discuss the implications.