The Cariban languages are an indigenous language family widespread across northern South America. This project will reconstruct sources of the inverse agreement system reconstructed to Proto-Cariban (Gildea 1998) and found in almost all modern languages of the family. Recent descriptive work on Pekodian Branch languages Bakairi (Meira 2003) and Inkpéng (Pacheco 2001) suggest that phonological loss of third-person marking might have given rise to a formally hierarchical pattern.