Evolutionary theory predicts that natural selection will fashion cognitive biases to guide when, and from whom, individuals acquire social information, but the precise nature of these biases, especially in ecologically valid group contexts, remains unknown. We exposed four captive groups of chimpanzees (Pan troglodytes) to a novel extractive foraging device and, by fitting statistical models, isolated four simultaneously operating transmission biases. These include biases to copy (i) higher-ranking and (ii) expert individuals, and to copy others when (iii) uncertain or (iv) of low rank. High-ranking individuals were relatively un-strategic in their use of acquired knowledge, which, combined with the bias for others to observe them, may explain reports that high innovation rates (in juveniles and subordinates) do not generate a correspondingly high frequency of traditions in chimpanzees. Given the typically low rank of immigrants in chimpanzees, a 'copying dominants' bias may contribute to the observed maintenance of distinct cultural repertoires in neighboring communities despite sharing similar ecology and knowledgeable migrants. Thus, a copying dominants strategy may, as often proposed for conformist transmission, and perhaps in concert with it, restrict the accumulation of traditions within chimpanzee communities whilst maintaining cultural diversity.

中文翻译：

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黑猩猩模仿占主导地位和知识渊博的个体：对文化多样性的影响。

进化论预测，自然选择将形成认知偏差，以指导个体何时、从谁那里获取社会信息，但这些偏差的确切性质，特别是在生态有效的群体背景下，仍然未知。我们将四组圈养的黑猩猩（Pan troglodytes）暴露在一种新型的采食装置中，并通过拟合统计模型，分离出四种同时运行的传输偏差。这些包括复制（i）较高级别和（ii）专家个人的偏见，以及在（iii）不确定或（iv）低级别时复制其他人的偏见。高层个人在使用所获得的知识时相对缺乏战略性，这与其他人观察他们的偏见相结合，可以解释高创新率（在青少年和下属中）并没有产生相应高频率传统的报道在黑猩猩中。鉴于黑猩猩的移民等级通常较低，“复制优势”偏见可能有助于观察到邻近社区中独特文化的保留，尽管它们具有相似的生态和知识渊博的移民。因此，正如人们经常为顺从传播所提出的那样，复制主导策略可能会限制黑猩猩群体内传统的积累，同时保持文化多样性。