The Comprehensive Assessment of Theory of Mind (CAT): A Novel Measure of 3- to 8-Year-Old Children's Theory of Mind and an Evaluation of Mental-State Scaling

Abstract

This study describes a novel measure of children's Theory of Mind (ToM) development—called the Comprehensive Assessment of ToM (CAT)—that addresses limitations in existing ToM measures. This behavioral measure includes three–six items each about diverse desires, diverse beliefs, knowledge access, knowledge expertise, false belief, and visual perspective taking, as well as nonsocial representational reasoning (i.e., false-sign). All items include a prediction, explanation, and general comprehension question. The measure is psychometrically valid and robust in 3- to 8-year-old children (n = 206; 104 boys; 101 girls; 1 gender fluid; 37.7% White non-Hispanic). Children's performance replicates prior findings with the commonly used Wellman and Liu (2004) ToM scale, but also reveals a novel and nuanced pattern of mental-state scaling over early to middle childhood.