The Communicative Mind

为什么人类学会了语言，而猿类却没有？根据一种标准观点（Tomasello 2008; Scott-Phillips 2014），只有人类才能习得语言，因为我们拥有心智理论（“ToM”）的生物适应性，即思考他人心理状态的能力，而这是类人猿所缺乏的。这使我们能够按照自然语言发展所必需的“Grice”（Grice 1957）交际意图行事并将其归因于此。由于类人猿缺乏ToM，它们既不能归因于交流意图，也不能习得语言。对于标准观点来说，有问题的是，希腊人交流所需的ToM似乎只有在孩子四岁左右掌握了某些自然语言形式（“现实补语从句”语法）后才会发展。如果格里斯交际所需要的读心术本身依赖于语言，那么它就不能解释儿童的语言习得。由于新的经验数据（Krupenye & Kano, 2017）也表明类人猿的ToM与不会说话的婴儿相似，标准观点无法解释类人猿缺乏语言的原因。为了解决这些解释难题，“交际思维”项目将对ToM、语言和交流之间的关系进行新的解释。PI先前的研究表明，婴儿和猿类都可以参与社会认知上不需要要求的“最低限度的Gricean”交流形式，在此基础上，该项目将确定人类和猿类之间关键的社会认知差异是文化上习得的，而不是生物学上遗传的。它们的出现是因为人类（猿类除外）可以使用有句法结构的话语进行交流，而且由于这种能力，一代又一代的语言使用者已经开发出了将心理状态理论化的语言工具。因此，不是ToM解释了语言的发展，而是语法和语言的文化演变解释了ToM的发展。儿童通过对话和讲故事的文化实践，在个体发育中学习使用这些工具，从而获得思考心灵的新工具。《交际心理》将从系统发育和个体发育的角度对语言的进化和ToM的发展进行新的解释。在项目的第一年和第二年，PI（一位哲学家）将与一位发展心理学家合作，进行一系列开创性的研究，以阐明补语从句语法掌握与表达他人所知的能力之间的发展关系。通过首次使用语言和非语言范式来研究儿童对嵌入的、分层结构的补语子句形式的掌握发展，我们将对支持儿童读心和语言发展的认知机制产生新的认识。在项目的第三和第四年，PI将与语言学家合作，为人类历史上补语从句语法的出现提供新的视角。我们将对人类的认知结构在系统发育上的出现进行新的解释，这种结构允许我们，而不是我们的类人猿表亲，使用有句法结构的语言。随后，我们将使用现有语言的比较来发展自然语言中类似补语从句语法的文化演变。这些子项目将结合起来，说明使用语言表达他人对世界的看法的能力的文化起源。我们将展示如何通过交际互动的过程来创建和学习ToM的语言工具，并描述他们灌输给说话者的新的表征工具。通过展示人类独特的认知特征是通过交流产生的，我们将展示人类思想的根本社会基础。随后，我们将利用我们的发现开发教育工具来支持儿童的学习。

Why do humans but not apes acquire language?According to a standard view (Tomasello 2008; Scott-Phillips 2014) humans alone acquire language because we possess biological adaptations for Theory of Mind ('ToM') - the ability to think about others' mental states - that great apes lack. These enable us to act with and attribute the 'Gricean' (Grice 1957) communicative intentions that are necessary for natural language development. Since great apes lack ToM, they can neither attribute communicative intentions nor acquire language. Problematically for the standard view, the ToM needed for Gricean communication seem to develop only with the mastery of certain natural language forms - 'realis complement clause' syntax - around children's fourth birthday. If the mindreading needed for Gricean communication is itself language dependent, then it cannot contribute to an explanation of children's language acquisition. Since new empirical data (Krupenye & Kano, 2017) also shows that the ToM of great apes is similar to that of pre-verbal infants, the standard view leaves the absence of language in great apes unexplained.To dissolve these explanatory puzzles, the Communicative Mind project will develop a new account of the relationship between ToM, language, and communication. Building on the PI's previous work, which shows that infants and apes alike can engage in socio-cognitively undemanding forms of 'minimally Gricean' communication, the project will establish that key socio-cognitive differences between humans and apes are culturally learned, not biologically inherited. They emerge because humans but not apes can use syntactically structured utterances to communicate, and because on the back of this ability generations of language-users have developed linguistic tools for theorising about mental states. Thus, it is not ToM that explains the development of language, but syntax and the cultural evolution of language that explains the development of ToM. Children learn to use these tools in ontogeny, through cultural practices of conversation and storytelling, and thereby acquire new tools for thinking about minds. The Communicative Mind will develop new accounts of the evolution of language in phylogeny, and of the development of ToM in ontogeny. In years 1 and 2 of the project, the PI (a philosopher) will work with a developmental psychologist to conduct a series of pioneering studies to illuminate the developmental relationship between complement clause syntax mastery and the ability to represent what others know. By using, for the first time, both verbal and non-verbal paradigms to study the development of children's mastery of embedded, hierarchically structured complement clause forms, we will generate new knowledge of the cognitive mechanisms that support the development of children's mindreading and language. In years 3 and 4 of the project, the PI will work with a linguist to shed new light on the emergence of complement clause syntax in human history. We will develop a new account of the phylogenetic emergence in humans of a cognitive architecture that allows us, but not our great ape cousins, to use syntactically structured language. Subsequently we will use comparisons of existing languages to develop an account of the cultural evolution of complement-clause like syntax in natural languages. These subprojects will combine to give an account of the cultural origins of the ability to use language to represent others' perspectives on the world. We will show how linguistic tools for ToM can be created and learned through processes of communicative interaction, and describe the new representational tools with which they imbue speakers. By showing that uniquely human cognitive traits emerge through communication, we will demonstrate the fundamentally social foundations of human thought. Subsequently we will use our findings to develop educational tools to support children's learning.