Validation of the "Theory of Mind" Scale

This study investigated the validity of Wellman and Liu's (2004) Theory-of-Mind Scale in a German translation (Hofer & Aschersleben, 2004); testing a sample of N=107 German children aged 3 to 5. Our results confirm a stepwise conceptual progression and replicate the scaling of the tasks: In contrast to Wellman and Liu (2004), we found an order effect with better fit and performance when the tasks were presented ordered by increasing difficulty rather than in an arbitrary order. Thus, the results indicate that the German version of the Theory-of-Mind Scale reflects the development of children's understanding of the mental domain during preschool years and provides an informative instrument for measuring individual children's theory of mind competencies.