Deictic and sociopragmatic effects in Tibeto-Burman SAP indexation

The study of hierarchical argument indexation systems shows that while the ranking of both 1st and 2nd person over other arguments is robust and reliable, it is impossible to find any compelling crosslinguistic evidence for one or the other ranking of the two Speech Act Participants, and rare to find a consistent ranking even within a single language. This paper assembles and reviews historical changes in the indexation of the "local" categories (1→2 and 2→1) in a number of Tibeto-Burman languages. We see that the fundamental deictic ranking SAP > 3 is conservative, and inverse marking to emphasize that ranking has been reinvented several times in the family. Changes in the marking of local categories are more diverse, but two phenomena recur independently in different languages and branches: a tendency for the 1→2 form to be uniquely marked, sometimes with forms which are not synchronically relatable to anything else in the paradigm, and a contrasting tendency for the 2→1 form to merge with the marking of 3→1. I propose that these tendencies reflect what I call sociopragmatic effects, i.e. the socially delicate nature of any and all natural utterances involving both the speaker and the addressee.