Theory of mind, mental state talk, and discourse comprehension: Theory of mind process is more important for narrative comprehension than for informational text comprehension.

We investigated the relations among theory of mind (ToM), mental state talk, and discourse comprehension. Specifically, we examined the frequency of mental state talk in children's oral recall of narrative texts and informational texts as well as relations among ToM, mental state talk (inclusion of mental state words in the recall of narrative and informational texts), and narrative and informational text comprehension. Results from children in Grade 4 (N = 132; Mage = 10.39 years) revealed that a greater number of mental state talk instances appeared in children's recall of narrative texts than in their recall of informational texts, but the mean number also differed across texts within a genre. ToM skill predicted the extent of mental state talk in narrative texts and informational texts, and the relation was stronger for narrative texts than for informational texts, after accounting for vocabulary, grammatical knowledge, working memory, and attentional control. Mental state talk in narrative texts was extremely strongly related to narrative comprehension, whereas mental state talk in informational texts was weakly related to informational text comprehension. Results suggest that ToM skill relates to mental state talk in the recall of texts, and both ToM and mental state talk play greater roles in comprehension of narrative texts than in comprehension of informational texts.