Primates have relatively larger brains than other mammals even though brain tissue is energetically costly. Comparative studies of variation in cognitive skills allow testing of evolutionary hypotheses addressing socioecological factors driving the evolution of primate brain size. However, data on cognitive abilities for meaningful interspecific comparisons are only available for haplorhine primates (great apes, Old- and New World monkeys) although strepsirrhine primates (lemurs and lorises) serve as the best living models of ancestral primate cognitive skills, linking primates to other mammals. To begin filling this gap, we tested members of three lemur species (Microcebus murinus, Varecia variegata, Lemur catta) with the Primate Cognition Test Battery, a comprehensive set of experiments addressing physical and social cognitive skills that has previously been used in studies of haplorhines. We found no significant differences in cognitive performance among lemur species and, surprisingly, their average performance was not different from that of haplorhines in many aspects. Specifically, lemurs’ overall performance was inferior in the physical domain but matched that of haplorhines in the social domain. These results question a clear-cut link between brain size and cognitive skills, suggesting a more domain-specific distribution of cognitive abilities in primates, and indicate more continuity in cognitive abilities across primate lineages than previously thought.

中文翻译：

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狐猴基线：灵长类认知测试电池中狐猴与猴子和猿的比较


灵长类动物的大脑比其他哺乳动物更大，尽管脑组织的能量消耗很大。对认知技能变化的比较研究可以测试进化假设，解决驱动灵长类动物大脑尺寸进化的社会生态因素。然而，尽管链球菌灵长类动物（狐猴和懒猴）是祖先灵长类动物认知技能的最佳活体模型，但有关有意义的种间比较的认知能力数据仅适用于哈普罗灵长类动物（类人猿、旧世界猴和新世界猴）。其他哺乳动物。为了开始填补这一空白，我们使用灵长类认知测试电池测试了三种狐猴物种（Microcebus murinus、Varecia variegata、Lemur catta）的成员，这是一套全面的实验，旨在解决身体和社会认知技能，以前曾用于单嗅动物的研究。我们发现狐猴物种之间的认知表现没有显着差异，令人惊讶的是，它们的平均表现在许多方面与单鼻狐猴没有什么不同。具体来说，狐猴在身体领域的整体表现较差，但在社会领域的表现与单鼻猴相当。这些结果对大脑大小和认知技能之间的明确联系提出了质疑，表明灵长类动物的认知能力分布更具有特定领域性，并且表明灵长类动物谱系中认知能力的连续性比之前认为的更大。