Children rapidly learn a tremendous amount about languagedespite limitations imposed on them by their developing cog-nitive abilities. One possible explanation for this rapid learn-ing is that caregivers tune the language they produce tothese limitations, titrating the complexity of their speech todevelopmentally-appropriate levels. We test this hypothesis ina large-scale corpus analysis, measuring the contingency be-tween parents’ and children’s speech over the first 5 years.Our results support the linguistic tuning hypothesis, showinga high degree of mostly parent-led coordination early in de-velopment that decreases as children become more proficientlanguage learners and users.
