Taking theory of mind research into much needed new terrain - a commentary on Kochanska et al. (2025).

Contemporary research on developing theory of mind emphasizes its cognitive and neurobiological foundations, but studies of its relational origins have potential for opening new terrain in this expansive literature. The study by Kochanska and colleagues shows this in several ways. First, it offers a model for constructing theoretically guided causal models built on longitudinal research enlisting multiple predictors of developing theory of mind that can be examined in concert. Second, the findings invite deeper consideration of the processes by which theory of mind emerges by unpacking the relational predictors highlighted in this and other studies. In particular, examining the characteristics of early conversation focused on the child's experiences and mental states and studying the coordination of subjective states in parent-child interaction are each warranted avenues. Third, enlisting fathers and mothers into this inquiry broadens the range of relational partners contributing to young children's developing understanding of the mind.