Across a diverse range of languages, children proceed through similar stages in their production of causal language: their initial verbs lack internal causal structure, followed by a period during which they produce causative overgeneralizations, indicating knowledge of a productive causative rule. We asked in this study whether a child not…

The question is addressed whether a child would develop a communication system if a conventional linguistic model is absent. Six congenitally deaf children, who were not exposed to Sign Language, were observed and videotaped at play in their homes at intervals of one to three months. The children ranged in age from 1 year, 5 months to 4 years, 1…