Sex differences moderate the relationship between adolescent language and mentalization.

Mentalization refers to the ability to infer mental states of self and others, and this capacity facilitates social interactions. Advances in mentalization theory have proposed that there are both explicit and implicit mentalizing capacities and language may be identified as being an important factor in differentiating these two components of mentalization. Moreover, given apparent sex differences in language and mentalization, we hypothesized that sex may moderate the relationship between language and mentalization. In this study, measures assessing implicit and explicit mentalization as well as language were examined in 49 adolescents (25 girls and 24 boys) aged 14 to 18 years. Participants were administered the Mentalizing Stories for Adolescents to assess explicit mentalization, and the Reading Mind in the Eyes Task to assess implicit mentalization. Language was assessed using the Clinical Evaluation of Language Fundamentals. Sex was found to moderate the relationship between language and explicit mentalization; while language and explicit mentalization were related in boys, these domains were unrelated in girls. There was no moderation of language and implicit mentalization by sex, and these two domains were also uncorrelated. These findings suggest an important role for language development in the capacity for explicit mentalization in boys, and we interpret this as a benefit in girls who may be more socially motivated and less limited by language in their efforts to mentalize.