In this study the authors investigated whether training preschool children in the use of mental state lexicon plays a significant role in bringing about advanced conceptual understanding of mental terms and improved performance on theory-of-mind tasks. A total of 70 participants belonging to two age groups (3 and 4 years old) were randomly assigned to experimental and control conditions. All participants were pretested and posttested with linguistic and cognitive measures. Analyses of pretest data did not show any significant differences between experimental and control groups. During a 2-month period of intervention, children were read stories enriched with mental lexicon. After listening to a story, the experimental group took part in language games and conversations aimed at stimulating children to use mental terms. In contrast, the control group did not participate in any special linguistic activities. The results show that training had a significant effect on emotion understanding and metacognitive vocabulary comprehension in the 3-year-old group and on false-belief understanding and metacognitive vocabulary comprehension in the 4-year-old group.

The present study investigates whether training preschool children in the active use of emotional state talk plays a significant role in bringing about greater understanding of emotion terms and improved emotion comprehension. Participants were 100 preschool children (M=52 months;SD=9·9; range: 35–70 months), randomly assigned to experimental or control conditions. They were pre- and post-tested to assess their language comprehension, metacognitive language comprehension and emotion understanding. Analyses of pre-test data did not show any significant differences between experimental and control groups. During the intervention phase, the children were read stories enriched with emotional lexicon. After listening to the stories, children in the experimental group took part in conversational language games designed to stimulate use of the selected emotional terms. In contrast, the control group children did not take part in any special linguistic activities after the story readings. Analyses revealed that the experimental group outperformed the control group in the understanding of inner state language and in the comprehension of emotion.