Proceedings of the Annual Meeting of the Cognitive Science Society

Variation in natural language is constrained: languages tend to lose competing variants over time, and where vari-ation persists, its use tends to be conditioned on grammatical or sociolinguistic context. We had adult participants learn andcommunicate with artificial languages exhibiting unpredictable variation in plural marking. Using an iterated learning pro-cedure, the languages produced by participants were used as training languages for other participants. We passed on eitherthe language produced during a post-training recall test (Recall condition) or the language used while communicating withanother participant (Interaction condition). We found that alignment during interaction leads to the elimination of variability:in Interaction chains, one plural marker typically came to dominate. However, in Recall chains, variation became conditionedon linguistic context, rather than being eliminated. This suggests that the pattern of restricted, conditioned variation in naturallanguage reflects the combined influences of biases in learning, recall and interaction.