Development and psychometric evidence of the Chinese Version of the Theory of Mind Inventory-2 (ToMI-2) in children with autism spectrum disorder

Background: Theory of mind (ToM) is an important social cognitive ability of humans to understand the mental states of themselves and others. Children with autism spectrum disorder (ASD) are believed to have impaired ToM. In this study, for application in Chinese children with ASD in clinical and research settings, the Chinese Version of the Theory of Mind Inventory-2 (ToMI-2-C) was developed with cultural adaptations. The psychometric properties of ToMI-2-C were then evaluated in Chinese children with ASD. Methods: The ToMI-2-C was developed and culturally adapted through a standard translation process: forward translation, back-translation, synthesis, expert validation and content validity, and a pilot study. A total of 166 children with ASD and 54 children with typical development, all aged 3–12 years, were then assessed with the ToMI-2-C and with measures of symptom severity, social adaptive behavior skills, and verbal ability. Results: The ToMI-2-C was found to have high internal consistency (Cronbach's α = 0.965) and good test–retest reliability (Intraclass correlation coefficient = 0.88), convergent validity (r = − 0.436 to 0.591, all p < 0.001), and discriminative validity (t = 8.172, p < 0.01; Cohen's d = 1.57; area-under-the-curve = 0.87) for differentiating children with ASD and those with typical development. Conclusions: The empirical results show that the ToMI-2-C could be a useful measure for clinicians and researchers to reliably and validly evaluate the daily performance of ToM in children with ASD.