What 'you' and 'I' mean to each other: Person indexicals, self-ascription, and theory of mind

This article offers a DE SE THEORY of person indexicals, wherein first- and second-person indexical pronouns indicate REFERENCE DE SE (also called SELF-ASCRIPTION). Long observed for first-person pronouns (Castañeda 1977, Kaplan 1977, Perry 1979, inter alia), self-ascription is extended here to second person as well. The person feature of a pronoun specifies the speech-act roles that must be played by the self-ascribers: the speakers (uttering a first-person pronoun), the addressees (interpreting a second-person pronoun), or both (for first-person inclusive). Other agents who are not among the designated self-ascribers for a given pronoun interpret the pronoun indirectly by inferring the self-ascriber's interpretation, a process requiring THEORY OF MIND, that is, the cognitive ability to impute mental states to others (Premack & Woodruff 1978). This de se theory is supported by convergent evidence from multiple domains: (i) It explains a typological universal: first- and second-person plurals always allow associative semantics ('speaker(s) plus others', 'addressee(s) plus others') rather than requiring regular plural semantics ('speakers only', 'addressees only') (Greenberg 1988, Noyer 1992, Cysouw 2003, Bobaljik 2008). (ii) It belongs to a family of approaches that solve the problem of the essential indexical (Perry 1979). (iii) It correctly predicts observed patterns of indexical pronoun production and comprehension by two populations lacking a fully developed theory of mind: typically developing children in the stage before theory of mind has developed, and children with autism. (iv) It correctly predicts the interpretation of second-person pronouns in utterances with multiple addressees.