Tecwyn Emma C, Denison Stephanie, Messer Emily J E, Buchsbaum Daphna
School of Psychology and Neuroscience, University of St Andrews, St Andrews, Scotland, UK.
Department of Psychology, University of Toronto, Toronto, Canada.
Anim Cogn. 2017 Mar;20(2):243-256. doi: 10.1007/s10071-016-1043-9. Epub 2016 Oct 15.
The ability to reason about probabilities has ecological relevance for many species. Recent research has shown that both preverbal infants and non-human great apes can make predictions about single-item samples randomly drawn from populations by reasoning about proportions. To further explore the evolutionary origins of this ability, we conducted the first investigation of probabilistic inference in a monkey species (capuchins; Sapajus spp.). Across four experiments, capuchins (N = 19) were presented with two populations of food items that differed in their relative distribution of preferred and non-preferred items, such that one population was more likely to yield a preferred item. In each trial, capuchins had to select between hidden single-item samples randomly drawn from each population. In Experiment 1 each population was homogeneous so reasoning about proportions was not required; Experiments 2-3 replicated previous probabilistic reasoning research with infants and apes; and Experiment 4 was a novel condition untested in other species, providing an important extension to previous work. Results revealed that at least some capuchins were able to make probabilistic inferences via reasoning about proportions as opposed to simpler quantity heuristics. Performance was relatively poor in Experiment 4, so the possibility remains that capuchins may use quantity-based heuristics in some situations, though further work is required to confirm this. Interestingly, performance was not at ceiling in Experiment 1, which did not involve reasoning about proportions, but did involve sampling. This suggests that the sampling task posed demands in addition to reasoning about proportions, possibly related to inhibitory control, working memory, and/or knowledge of object permanence.
对概率进行推理的能力对许多物种都具有生态相关性。最近的研究表明，尚不能言语的婴儿和非人类的大猩猩都能够通过对比例进行推理，对从总体中随机抽取的单项样本做出预测。为了进一步探究这种能力的进化起源，我们首次对一种猴子（卷尾猴；僧面猴属物种）的概率推理进行了研究。在四项实验中，向19只卷尾猴展示了两批食物，这两批食物在偏好食物和非偏好食物的相对分布上有所不同，以至于其中一批食物更有可能产生偏好食物。在每次试验中，卷尾猴必须在从每批食物中随机抽取的隐藏单项样本之间进行选择。在实验1中，每批食物都是同质的，因此不需要对比例进行推理；实验2 - 3重复了先前针对婴儿和大猩猩的概率推理研究；实验4是一个在其他物种中未测试过的新条件，为先前的研究提供了重要扩展。结果显示，至少一些卷尾猴能够通过对比例进行推理来做出概率推断，而不是采用更简单的数量启发法。在实验4中表现相对较差，所以卷尾猴在某些情况下可能使用基于数量的启发法这种可能性仍然存在，不过还需要进一步研究来证实这一点。有趣的是，在不涉及对比例进行推理但涉及抽样的实验1中，表现并未达到上限。这表明抽样任务除了对比例进行推理之外还提出了要求，可能与抑制控制、工作记忆和/或客体永久性知识有关。
