To illustrate the embodied and embedded nature of infant learning, I present several studies from our lab on infants’ exposure to different word classes in the ecologically-valid home environment. We videorecorded infants (12-24 months) and mothers during natural home activities (1 to 2 hours per visit, Ns=30-100). We transcribed interactions and identified all concrete nouns in mothers’ speech. We also marked mothers’ use of verbs and ‘math words’— adjectives and prepositions that refer to numbers, quantities (more, less), spatial relations (under, on top of), shapes, and magnitudes (big, long).

Annotations of the timing, behaviors, and contexts of infants’ speech exposure revealed several impactful characteristics: (1) Words in mothers’ speech contained high regularity in temporal structure. For example, mothers used the same word in a bout of repetition (e.g., dog, dog, dog; up, up, up) and they referenced objects from the same taxonomic category (e.g., animals) within a tight time window (e.g., dog, cat, horse); (2) Mothers provided multimodal input (speech with gesture/touch) that functioned to highlight word meaning; (3) Infants’ own actions were a reliable impetus for word exposure (e.g., verbs and spatial terms like walk, jump, down referred to infants’ movements through space), and (4) High regularity characterized the activity and location contexts of infants’ exposure to particular words (e.g., food nouns and words for magnitudes were frequent during snack time). Notably, characteristics of infants’ home experiences and language interactions predicted individual differences in skills across domains—including sustained attention, vocabulary growth, the production of words during interactions, school readiness and academic achievement years later. We discuss implications for theories of word learning and language interventions.