A central challenge in language acquisition is the integration of multiple sources of information, potentially in conflict, to acquire new knowledge and adjust current linguistic representations.One way to accomplish this is to assign more weight to more reliable sources of information in context. We test the hypothesis that children adjust the weight of different sources of information during learning, considering two specific sources of information: their knowledge of the meaning of familiar words (semantics) and their familiarity with syntax. We varied the reliability of these sources of information through an induction phase (reliable-syntax or reliable-semantics). At test, French 4-5-year-old children and adults listened to sentences where information provided by these two cues conflicted, and were asked to choose between two videos that illustrate the sentence. One video presented the reasonable choice if the sentence is assumed to be syntactically correct, but familiar words refer to novel things (e.g., une mange -"an eats" describes a novel object). The other video was the reasonable choice if the sentence is assumed to be syntactically incorrect and familiar words' meaning is preserved (e.g., "an eats" describes a girl eating, and should have actually been "she eats"). As predicted, the proportion of syntactic choices (e.g., interpreting mange -"eats", as a novel noun) was found to be higher in the reliable-syntax condition than in the reliable-semantics condition, showing that children and adults can adapt their expectations to the reliability of sources of information.

A central challenge in language acquisition is the integration of multiple sources of information, potentially in conflict, to acquire new knowledge and adjust current linguistic representations. One way to accomplish this is to assign more weight to more reliable sources of information in context. We test the hypothesis that children adjust the weight of different sources of information during learning, considering two specific sources of information: their knowledge of the meaning of familiar words (semantics) and their familiarity with syntax. We varied the reliability of these sources of information through an induction phase (reliable-syntax or reliable-semantics). At test, French 4-5-year-old children and adults listened to sentences where information provided by these two cues conflicted, and were asked to choose between two videos that illustrate the sentence. One video presented the reasonable choice if the sentence is assumed to be syntactically correct, but familiar words refer to novel things (e.g., une mange - "an eats" describes a novel object). The other video was the reasonable choice if the sentence is assumed to be syntactically incorrect and familiar words’ meaning is preserved (e.g., "an eats" describes a girl eating, and should have actually been "she eats"). As predicted, the proportion of syntactic choices (e.g., interpreting mange - "eats", as a novel noun) was found to be higher in the reliable-syntax condition than in the reliable-semantics condition, showing that children and adults can adapt their expectations to the reliability of sources of information.