Proceedings of the Annual Meeting of the Cognitive Science Society

Cross-linguistically prevalent semantic distinctions are widely assumed to be easier to learn, due to the naturalness of the underlying concepts. Here we propose that pragmatic pressures can also shape this cross-linguistic prevalence, and offer evidence from evidentiality (the encoding of information source). Languages with grammatical evidential systems overwhelmingly encode indirect sources (reported information or hearsay) but very rarely mark direct, visual experience. Conceptually, humans reason naturally about what they see, however, on pragmatic grounds, when encoding a single source, reported information is more informative because it is potentially unreliable and consequently more marked. In two Artificial Language Learning experiments, we directly compared the learnability of two simple evidential systems, each marking only a visual or reportative source. Across experiments, participants learned more easily to mark reportative information sources. Our results provide support for a pragmatic bias that shapes both the cross-linguistic frequency and the learnability of evidential semantic distinctions.