Learners restrict their linguistic generalizations using preemption but not entrenchment: Evidence from artificial-language-learning studies with adults and children.

A central goal of research into language acquisition is explaining how, when learners generalize to new cases, they appropriately restrict their generalizations (e.g., to avoid producing ungrammatical utterances such as *the clown laughed the man; "*" indicates an ungrammatical form). The past 30 years have seen an unresolved debate between statistical preemption and entrenchment as explanations. Under preemption, the use of a verb in a particular construction (e.g., *the clown laughed the man ) is probabilistically blocked by hearing that other verb constructions with similar meanings only (e.g., the clown made the man laugh ). Under entrenchment, such errors (e.g., * the clown laughed the man ) are probabilistically blocked by hearing any utterance that includes the relevant verb (e.g., by the clown made the man laugh and the man laughed ). Across five artificial-language-learning studies, we designed a training regime such that learners received evidence for the (by the relevant hypothesis) ungrammaticality of a particular unattested verb/noun + particle combination (e.g., * chila + kem ; * squeako + kem ) via either preemption only or entrenchment only. Across all five studies, participants in the preemption condition (as per our preregistered prediction) rated unattested verb/noun + particle combinations as less acceptable for restricted verbs/nouns, which appeared during training, than for unrestricted, novel-at-test verbs/nouns, which did not appear during training, that is, strong evidence for preemption. Participants in the entrenchment condition showed no evidence for such an effect (and in 3/5 experiments, positive evidence for the null). We conclude that a successful model of learning linguistic restrictions must instantiate competition between different forms only where they express the same (or similar) meanings. (PsycInfo Database Record (c) 2024 APA, all rights reserved).