Department of Anthropology, University of California Los Angeles, 375 Portola Plaza, Los Angeles, CA 90095, USA; Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, PO Box 874101, Tempe, AZ 85287-4101, USA.
Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, PO Box 874101, Tempe, AZ 85287-4101, USA.
Curr Biol. 2021 Apr 26;31(8):1798-1803.e3. doi: 10.1016/j.cub.2021.01.096. Epub 2021 Feb 24.
Humans occupy a wider range of environments, process more energy, and have greater biomass than any other species because we are able to culturally evolve complex, locally adaptive technologies. Competing models make different predictions about the role of causal knowledge in this process. Some argue that innovation and transmission cannot occur without causal understanding, while others posit that complex technologies can evolve without causal understanding. Prior research on this topic has been restricted to theoretical work and experimental studies with student participants. The Hadza are foragers who rely on bows for subsistence. We interviewed skilled Hadza bowyers (bow-makers) and compared their beliefs regarding the tradeoffs in bow construction to those revealed by experimental and engineering research. If bowyers understand the tradeoffs, it is plausible that cultural evolution is rooted in causal understanding, while if they do not, the cultural accumulation of knowledge is likely more important in the process. We show that Hadza bowyers understand some mechanical trade-offs but not others, and therefore the evolution of a complex, highly adaptive technology is possible with incomplete causal knowledge regarding key mechanical trade-offs. Instead, some important design choices made by subjects seem to reflect cultural norms. Although previously published reports have suggested that some individuals are recognized by the Hadza as being especially skilled or knowledgeable, our results do not indicate that some individuals are significantly more knowledgeable about bow-making than others, nor is there statistical evidence that causal knowledge increases with age.
人类占据了更广泛的环境，消耗了更多的能量，拥有比任何其他物种更大的生物量，因为我们能够在文化上进化出复杂的、适应当地环境的技术。竞争模型对因果知识在这个过程中的作用做出了不同的预测。一些人认为，如果没有因果理解，创新和传播就不可能发生，而另一些人则认为，复杂的技术可以在没有因果理解的情况下进化。关于这个主题的先前研究仅限于理论工作和有学生参与者的实验研究。哈扎人是依靠弓箭为生的觅食者。我们采访了熟练的哈扎弓箭制造者（制弓者），并将他们对弓箭制造权衡的看法与实验和工程研究揭示的看法进行了比较。如果弓箭制造者理解权衡取舍，那么文化进化很可能是基于因果理解的，而如果他们不理解，那么文化知识的积累在这个过程中可能更重要。我们表明，哈扎弓箭制造者理解一些机械权衡取舍，但不是其他的，因此，即使对关键机械权衡取舍的因果知识不完全，复杂的、高度适应的技术也可能进化。相反，一些重要的设计选择似乎反映了文化规范。尽管之前的报告表明，一些人被哈扎人认为是特别有技能或知识的，但我们的结果并不表明有些人在制弓方面比其他人更有知识，也没有统计证据表明因果知识会随着年龄的增长而增加。
