@INPROCEEDINGS { vantrijp:10a, address = {Singapore},author = {van Trijp, Remi},booktitle = {The Evolution of Language (EVOLANG 8)},editor = {Smith, A.D.M. and Schouwstra, M. and de Boer, B. and Smith, K.},note = {Language},pages = {336--343},publisher = {World Scientific},title = {Strategy Competition in the Evolution of Pronouns: A Case-Study of Spanish Leísmo, Laísmo and Loísmo},type = {INPROCEEDINGS},year = {2010},abstract = {Pronouns form a particularly interesting part-of-speech for evolutionary linguistics because their development is often lagging behind with respect to other changes in their language. Many hypotheses on pronoun evolution exist ? both for explaining their initial resilience to change as well as for why they eventually cave in to evolutionary pressures ? but so far, no one has proposed a formal model yet that operationalizes these explanations in a unified theory. This paper therefore presents a computational model of pronoun evolution in a multi-agent population; and argues that pronoun evolution can best be understood as an interplay between the level of language strategies, which are the procedures for learning, expanding and aligning particular features of language, and the level of the specific language systems that instantiate these strategies in terms of concrete words, morphemes and grammatical structures. This claim is supported by a case study on Spanish pronouns, which are currently undergoing an evolution from a case- to a referential-based system, the latter of which there exist multiple variations (which are called Leísmo, Laísmo and Loísmo depending on the type of change).}}