Language Evolution and Computation Bibliography

Languages of the world display many structural similarities. We test the hypothesis that some of these structural properties may arise from biases operating during language acquisition that shape languages over time. Specifically, we investigate whether language learners are biased toward linguistic systems that strike an efficient balance between robust information transfer, on the one hand, and effort or resource demands, on the other hand, thereby increasing the communicative utility of the acquired language. In two experiments, we expose learners to miniature artificial languages designed in such a way that they do not use their formal devices (case marking) efficiently to facilitate robust information transfer. We find that learners restructure such languages in ways that facilitate efficient information transfer compared with the input language. These systematic changes introduced by the learners follow typologically frequent patterns, supporting the hypothesis that some of the structural similarities found in natural languages are shaped by biases toward communicatively efficient linguistic systems.

In this article we investigate what learners acquire when their input contains in- consistent grammatical morphemes such as those present in pidgins and incipi- ent creoles. In particular, we ask if learners acquire variability veridically or if they change it, making the language more regular as they learn it. In Experi- ment 1 we taught adult participants an artificial language containing unpredict- able variation in 1 grammatical feature. We manipulated the amount of inconsis- tency and the meaning of the inconsistent item. Postexposure testing showed that participants learned the language, including the variable item, despite the presence of inconsistency. However, their use of variable items reflected their input. Participants exposed to consistent patterns produced consistent patterns, and participants exposed to inconsistency reproduced that inconsistency; they did not make the language more consistent. The meaning of the inconsistent item had no effect. In Experiment 2 we taught adults and 5- to 7-year-old chil- dren a similar artificial language. As in Experiment 1, the adults did not regu- larize the language. However, many children did regularize the language, impos- ing patterns that were not the same as their input. These results suggest that children and adults do not learn from variable input in the same way. Moreover, they suggest that children may play a unique and important role in creole for- mation by regularizing grammatical patterns.