School of Psychology and Neuroscience, University of St Andrews, Scotland, UK.
Sci Adv. 2018 Nov 14;4(11):eaau3401. doi: 10.1126/sciadv.aau3401. eCollection 2018 Nov.
One of the defining features of language is displaced reference-the capacity to transmit information about something that is not present or about a past or future event. It is very rare in nature and has not been shown in any nonhuman primate, confounding, as such, any understanding of its precursors and evolution in the human lineage. Here, we describe a vocal phenomenon in a wild great ape with unparalleled affinities with displaced reference. When exposed to predator models, Sumatran orangutan mothers temporarily suppressed alarm calls up to 20 min until the model was out of sight. Subjects delayed their vocal responses in function of perceived danger for themselves, but four major predictions for stress-based mechanisms were not met. Conversely, vocal delay was also a function of perceived danger for another-an infant-suggesting high-order cognition. Our findings suggest that displaced reference in language is likely to have originally piggybacked on akin behaviors in an ancestral hominid.
语言的一个重要特征是指代的迁移，即传递关于不在场的事物或过去或未来事件的信息的能力。这种能力在自然界中非常罕见，也没有在任何非人类灵长类动物身上表现出来，这使得我们很难理解它在人类谱系中的前体和进化。在这里，我们描述了一种野生大型类人猿的发声现象，这种现象与指代的迁移具有无与伦比的亲和力。当苏门答腊猩猩的母亲暴露在捕食者模型下时，它们会暂时抑制警报声长达 20 分钟，直到模型消失在视线之外。研究对象根据感知到的自身危险延迟了发声反应，但有四个基于压力的机制的主要预测并没有得到满足。相反，发声延迟也是另一个对象（婴儿）感知到危险的函数，这表明存在高级认知。我们的发现表明，语言中指代的迁移可能最初是在一个祖先进化人类的类似行为基础上发展起来的。
