Causal understanding is not necessary for the improvement of culturally evolving technology

Bows and arrows, houses, and kayaks are just a few examples of the highly-optimized tools that humans produced and used to colonize new environments. Because there is much evidence that humans’ cognitive abilities are unparalleled, many believe that such technologies resulted from our superior causal reasoning abilities. However, others have stressed that the high dimensionality of human technologies make them very hard to understand causally. Instead, they argue that optimized technologies emerge through the retention of small improvements across generations without requiring understanding of how these technologies work. Here, we show that a physical artifact becomes progressively optimized across generations of social learners in the absence of explicit causal understanding. Moreover, we find that the transmission of causal models across generations has no noticeable effect on the pace of cultural evolution. The reason is that participants do not spontaneously create multidimensional causal theories but instead mainly produce simplistic models related to a salient dimension. Finally, we show that the transmission of these inaccurate theories constrains learners’ exploration and has downstream effects on their understanding. These results indicate that complex technologies need not result from enhanced causal reasoning but instead can emerge from the accumulation of improvements made across generations.

弓箭、房屋以及独木舟不过是人类所创造并运用以拓殖新环境的众多高度优化工具的少数实例。鉴于人类认知能力之卓越，众多学者坚信此类技术之产生源于我们卓越的因果推理能力。然而，亦有学者强调人类技术的多维性使其因果理解变得尤为困难。他们主张，优化技术的出现是通过代际间对微小改进的保留而逐渐形成，而不需要对这些技术的运作机制有深入的理解。在本研究中，我们揭示了在缺乏显性因果理解的情况下，物理遗物在代际社会学习者的作用下逐渐实现优化。此外，我们发现因果模型在代际间的传播对文化演化的速度并无显著影响。原因在于参与者并非自发构建多维因果理论，而是主要产生与显著维度相关的简单模型。最终，我们证明了这些不准确理论的传播限制了学习者的探索，并对他们的理解产生了下游影响。这些结果表明，复杂技术并非必然源于增强的因果推理能力，而是可能源于代际间改进的累积。