A longitudinal study of theory of mind across the lifespan

INTRODUCTION: Theory of Mind (ToM) is essential for social interactions. However, gaps remain in our knowledge of when ToM abilities develop and change, particularly from adolescence to older adulthood. METHODS: We used data from an ongoing longitudinal study to examine ToM abilities across three time points in participants aged 3 years and older. Testing waves occurred over multiple years. Cognitive ToM was assessed using the Sandbox task (N = 187; age range = 3-80 years), and affective ToM was assessed using the Reading the Mind in the Eyes Task (RMET; N = 121; age range = 6-80 years). Data were analyzed using mixed-design ANOVAs to examine interactions between Age Group and Time Point. RESULTS: Children aged 6-9 years exhibited significantly lower ToM abilities compared to adults. However, beyond childhood, both cognitive and affective ToM remained relatively stable across the lifespan. DISCUSSION: Our study illuminates critical periods of ToM development. Moreover, our study highlights the importance of using measures that capture subtle changes across the lifespan.