Understanding mind and emotion: longitudinal associations with mental-state talk between young friends.

Developmental changes in children's understanding of mind and emotion and their mental-state talk in conversations with friends were examined in a longitudinal study of 50 children (M age at each time point = 3 years 11 months, 4 years 6 months, 5 years 0 months). Significant and related improvements over time were found for both theory-of-mind task performance and affective perspective taking. Associated with these cognitive developments were quantitative and qualitative changes in children's references to mental states in their conversations with friends. Individual differences in theory of mind, emotion understanding, and mental-state talk were strikingly stable over the 13-month period. Although there were no gender differences in children's task performances, girls showed more frequent and more developed mental-state talk than boys.