Language and theory of mind: A longitudinal study of three- to four-year-olds

This longitudinal study investigated the causal relation between language and theory of mind by taking into account the contribution of working memory measures. Overall, 179 three-year-old children were tested twice with the same tasks assessing language development, theory of mind and working memory. The time interval between the measurement points was seven months. In line with previous studies, it was found that earlier language competence predicted later theory of mind but there was no reciprocal relation. There was no evidence for the assumption that the relationship between language and theory of mind is mediated by working memory as a common third factor. Taken together, the findings emphasize the relevance of language skills for theory of mind development.