Crosslinguistic Developmental Consistency in the Composition of Toddlers’ Internal State Vocabulary: Evidence from Four Languages

Mental state language, emerging in the second and third years of life in typically developing children, is one of the first signs of an explicit psychological understanding. While mental state vocabulary may serve a variety of conversational functions in discourse and thus might not always indicate psychological comprehension, there is evidence for genuine references to mental states (desires, knowledge, beliefs, and emotions) early in development across languages. This present study presents parental questionnaire data on the composition of 297 toddler-aged (30-to 32-month-olds) children’s internal state vocabulary in four languages: Italian, German, English, and French. The results demonstrated that across languages expressions for physiological states (e.g., hungry and tired) were among the most varied, while children’s vocabulary for cognitive entities (e.g., know and think) proved to be least varied. Further, consistent with studies on children’s comprehension of these concepts, across languages children’s mastery of volition terms (e.g., like to do and want) preceded their mastery of cognition terms. These findings confirm the cross-linguistic consistency of children’s emerging expression of abstract psychological concepts.