Word Repetition and Isolation are Intertwined in Children's Early Language Experiences.

Infants experience language in the context of a dynamic environment in which many cues co-occur. However, experimenters often reduce language input to individual cues a priori without considering how children themselves may experience incoming information, leading to potentially inaccurate conclusions about how learning works outside of the lab. Here, we examined the shared temporal dynamics of two historically separated cues that are thought to support word learning: repetition of the same word in nearby utterances, and isolation of individual word tokens (i.e., single-word utterances). In a large database of North American English, we found that word repetition and isolation frequently co-occurred in children's natural language experiences, and the extent to which they did so was linked to words' earlier age of acquisition. This investigation emphasizes children's experiences in time as a way to understand the learning cues in the language environment, which may help researchers build learning theories that are grounded in real-world structure.