Mental State Language Development in Children With Down Syndrome Versus Typical Development.

This study compared mental state language (talk about emotions, thoughts, intentions, etc.) used by 6- to 11-year-old children with Down syndrome (DS) to a younger typically developing (TD) comparison group matched by nonverbal cognition. We aimed to determine (1) whether mental state language use is delayed in DS relative to developmental expectations, and (2) if there are differences between groups in the association between mental state language and developmental factors (emotion knowledge, expressive language). Rate of mental state language use was significantly lower in the group with DS, but the number of different mental state terms was not significantly different. Nuanced patterns of similarity and difference emerged between groups regarding the association between mental state language and other developmental factors.