Conceptualizing Functioning Levels of Theory of Mind Ability and Performance in Preschool to School-Aged Autistic and Neurotypical Children.

Autistic children often show reduced theory of mind (ToM). However, existing ToM measures neither sufficiently distinguish ToM ability from performance nor interpret both scores effectively, limiting their interpretability and clinical utility. To resolve these limitations, we characterized the measurement-based functioning levels and correspondence between ToM ability and performance among preschool to school-aged children. Data from 288 autistic and 168 neurotypical children were analyzed using a multidimensional Rasch model. The functioning levels and correspondence were established using expected responses across statistically distinguishable ToM levels. The results revealed three levels of ToM ability-Early (failure on all items), Basic (success on desire-based emotion), and Advanced (success on all items)-and five levels of ToM performance: Pre-ToM (understanding needs and wants), Emerging (simple emotion recognition), Transition (first-order false belief), Premature (contextual understanding), and Mature (pragmatic understanding). Importantly, while ToM performance tended to improve with ToM ability, only 20% of the items were comparable with neurotypical children. In conclusion, our findings highlight a critical gap in autistic children and provide the first empirically derived functioning framework linking ToM ability and performance. Beyond theoretical contribution, this study offers a practical pathway toward valid assessments and tailored interventions that target children's specific social-cognitive needs.