Jang Haneul, Redhead Daniel
Institute for Advanced Study in Toulouse, Toulouse School of Economics, 1 Esplanade de l'Université, Toulouse cedex 06 31080, France.
Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig 04103, Germany.
PNAS Nexus. 2025 Sep 8;4(9):pgaf258. doi: 10.1093/pnasnexus/pgaf258. eCollection 2025 Sep.
Cultural transmission across generations is key to cumulative cultural evolution. While several mechanisms-such as vertical, horizontal, and oblique transmission-have been studied for decades, how these mechanisms change across the life course, beyond childhood, remains unclear. Furthermore, it is under-explored whether different mechanisms apply to distinct learning processes: long-term learning-where individuals invest time and effort to acquire skills-and short-term learning-where individuals share information of immediate use. To investigate the network structure of these two types of knowledge transmission-long-term learning of foraging skills and short-term learning of food location information-we present social network data (1,633 nominations) collected from all inhabitants (aged 4 to 75) of a BaYaka community in the Republic of the Congo. Applying latent network models that estimate and adjust for measurement biases typical to self-reported data, we find that the demographic structure of a population-age distribution, sex, kinship, and marriage-shapes the dynamics of community-wide knowledge transmission. Foraging skills are transmitted within smaller, sparser networks with limited reciprocity, whereas food location information is exchanged more widely and reciprocally among peers. Both long-term and short-term knowledge transmission extend into adulthood, with adults learning from older adults, peers, and marital partners, and sharing knowledge with younger generations. Crucially, individuals tend to report more accurately about the partners with whom they shared knowledge than about those from whom they received knowledge. Our findings provide important empirical evidence on how community-wide cultural transmission is structured by demography and perception, and how these factors operate across different learning processes in a contemporary foraging society.
跨代文化传播是累积性文化进化的关键。虽然垂直、水平和斜向传播等几种机制已经被研究了几十年，但这些机制在童年之后的人生历程中如何变化仍不清楚。此外，不同机制是否适用于不同的学习过程——个体投入时间和精力获取技能的长期学习，以及个体分享即时可用信息的短期学习——也尚未得到充分探索。为了研究这两种知识传播的网络结构——觅食技能的长期学习和食物位置信息的短期学习——我们展示了从刚果共和国一个巴亚卡社区的所有居民（年龄在4至75岁之间）收集的社会网络数据（1633份提名）。应用潜在网络模型来估计和调整自我报告数据中典型的测量偏差，我们发现人口的人口结构——年龄分布、性别、亲属关系和婚姻——塑造了全社区知识传播的动态。觅食技能在较小、较稀疏且互惠有限的网络中传播，而食物位置信息在同龄人之间更广泛且相互地交换。长期和短期知识传播都延伸到成年期，成年人向年长者、同龄人及婚姻伴侣学习，并与年轻一代分享知识。至关重要的是，个体往往对与其分享知识的伙伴的报告比对从其获取知识的伙伴的报告更准确。我们的研究结果为全社区文化传播如何由人口统计学和认知构建，以及这些因素如何在当代觅食社会的不同学习过程中发挥作用提供了重要的实证证据。
