Institute for Logic, Cognition, Language and Information, 20018 Donostia-San Sebastian, Spain.
Ikerbasque Foundation for Science, 48009 Bilbao, Spain.
Proc Natl Acad Sci U S A. 2023 Oct 17;120(42):e2300243120. doi: 10.1073/pnas.2300243120. Epub 2023 Oct 12.
Nonhuman great apes inform one another in ways that can seem very humanlike. Especially in the gestural domain, their behavior exhibits many similarities with human communication, meeting widely used empirical criteria for intentionality. At the same time, there remain some manifest differences, most obviously the enormous range and scope of human expression. How to account for these similarities and differences in a unified way remains a major challenge. Here, we make a key distinction between the expression of intentions (Ladyginian) and the expression of specifically informative intentions (Gricean), and we situate this distinction within a "special case of" framework for classifying different modes of attention manipulation. We hence describe how the attested tendencies of great ape interaction-for instance, to be dyadic rather than triadic, to be about the here-and-now rather than "displaced," and to have a high degree of perceptual resemblance between form and meaning-are products of its Ladyginian but not Gricean character. We also reinterpret video footage of great ape gesture as Ladyginian but not Gricean, and we distinguish several varieties of meaning that are continuous with one another. We conclude that the evolutionary origins of linguistic meaning lie not in gradual changes in communication systems, but rather in gradual changes in social cognition, and specifically in what modes of attention manipulation are enabled by a species' cognitive phenotype: first Ladyginian and in turn Gricean. The second of these shifts rendered humans, and only humans, "language ready."
非人类的大型猿类以一种看似非常人性化的方式相互交流。特别是在手势领域，它们的行为与人类交流表现出许多相似之处，符合广泛使用的意图意向的经验标准。与此同时，仍然存在一些明显的差异，最明显的是人类表达的巨大范围和广度。如何以统一的方式解释这些相似性和差异仍然是一个主要挑战。在这里，我们对意图的表达（Ladyginian）和特定信息意图的表达（Gricean）进行了关键区分，并将这种区分置于一种“特殊情况”的框架内，用于对不同的注意力操纵模式进行分类。因此，我们描述了大型猿类互动的明显倾向——例如，是二元而不是三元的，是关于此时此地而不是“转移”的，并且形式和意义之间具有高度的感知相似性——是其 Ladyginian 而不是 Gricean 特征的产物。我们还重新解释了大型猿类手势的视频片段，将其视为 Ladyginian 而不是 Gricean，并区分了几种连续的意义。我们得出结论，语言意义的进化起源不在于沟通系统的逐渐变化，而在于社会认知的逐渐变化，特别是在于物种认知表型所允许的注意力操纵模式：首先是 Ladyginian，继而又是 Gricean。第二个转变使人类，而且只有人类，“具备了语言能力”。
