Switch reference in Western South America
Switch reference systems occur in a number of languages spoken in a contiguous area in western South America, across language families, and even across macro culture areas (Andes and Amazon). At first sight, this is suggestive of contact-induced diffusion, but the different systems show rather a lot of variation. This paper gives an overview of the switch-reference structures found in Western South America, taking a multi-variate approach to the phenomenon. In addition, it discusses the likelihood of horizontal and vertical transmission hypotheses to explain the current distribution of switch reference in South America.