The Communicative Mind

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 (FLF1) is developing 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 establishes 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....