Inference by exclusion, or the ability to select a correct course of action by systematically excluding other potential alternatives, is a form of logical inference that allows individuals to solve problems without complete information. Current comparative research shows that several bird, mammal and primate species can find hidden food through inference by exclusion. Yet there is also wide variation in how successful different species are as well as the kinds of sensory information they can use to do so. An important question is therefore why some species are better at engaging in logical inference than others. Here, we investigate the evolution of logical reasoning abilities by comparing strepsirrhine primate species that vary in dietary ecology: frugivorous ruffed lemurs (Varecia spp.) and folivorous Coquerel's sifakas, Propithecus coquereli. Across two studies, we examined their abilities to locate food using direct information versus inference from exclusion and using both visual and auditory information. In study 1, we assessed whether these lemurs could make inferences when full visual and auditory information about the two potential locations of food were provided. In study 2, we then compared their ability to make direct inferences versus inferences by exclusion in both the visual and auditory domains. We found that these lemur species can use visual information to find food, but that only ruffed lemurs were also able to use auditory cues, mirroring differences in the complexity of their wild ecology. We further found that, unlike many anthropoid species tested to date, these strepsirrhine species failed to make inferences by exclusion. These results highlight the importance of natural history in understanding the evolution of logical inference and help reconstruct the deeper phylogeny of primate cognition.

中文翻译：

---

来自皱褶狐猴和狐猴视觉和听觉信息的逻辑推论

排除推理，或通过系统地排除其他潜在替代方案来选择正确行动方案的能力，是一种逻辑推理形式，允许个人在没有完整信息的情况下解决问题。目前的比较研究表明，几种鸟类、哺乳动物和灵长类动物可以通过排除推理找到隐藏的食物。然而，不同物种的成功程度以及它们可以用来实现这一目标的感官信息种类也存在很大差异。因此，一个重要的问题是为什么有些物种比其他物种更擅长进行逻辑推理。在这里，我们通过比较饮食生态不同的链环素灵长类动物物种来研究逻辑推理能力的演变：食果的皱褶狐猴（Varecia spp.）和食叶的 Coquerel's sifakas，Propithecus coquereli。在两项研究中，我们检查了他们使用直接信息与排除推断以及使用视觉和听觉信息来定位食物的能力。在研究 1 中，我们评估了当提供关于食物的两个潜在位置的完整视觉和听觉信息时，这些狐猴是否可以做出推断。在研究 2 中，我们然后比较了他们在视觉和听觉领域进行直接推理与通过排除进行推理的能力。我们发现这些狐猴物种可以使用视觉信息来寻找食物，但只有皱褶狐猴也能够使用听觉线索，这反映了它们野生生态复杂性的差异。我们进一步发现，与迄今为止测试的许多类人猿物种不同，这些链霉属物种未能通过排除做出推断。