The roles of cultural transmission and causal reasoning in the cultural evolution of technology

Humans are uniquely capable of producing highly efficient tools, but the extent to which this capacity depends on individual reasoning abilities remains unclear. In particular, the respective roles of causal and technical reasoning versus cultural transmission in driving technological improvement are the subject of long-standing debate. We address this question by directly manipulating causal and technical reasoning in transmission chains, where participants sequentially inherit and refine prior solutions. Across two transmission chain experiments, participants (n = 900) completed tasks under three conditions: (i) technical reasoning, involving physical tasks and intuitive physics; (ii) causal reasoning, where similar causal structures could be exploited without physical context; and (iii) pure cultural transmission, in which causal structures were removed. We found that cumulative improvement occurred across generations even in the absence of causal structure, demonstrating that cultural transmission alone can drive technological improvement. While causal reasoning accelerated early improvement by helping participants focus on promising regions of the design space, its impact diminished over time. Notably, technical reasoning offered no added benefit over causal reasoning. These results highlight the beneficial yet dispensable role of causal reasoning in the improvement of culturally evolving technology, and challenge the view that improvements guided by causal models depend on domain specific rather than domain-general reasoning abilities.