Growing out of your own mind: Reexamining the development of the self-other difference in the unexpected contents task

Abstract

The unexpected contents task is a well-established measure for studying young children's developing theory of mind. The task measures whether children understand that others have a false belief about a deceptive container and whether children can track the representational change in their own beliefs about the container's contents. Performance on both questions improves between the ages of 3 and 4. A previous meta-analysis (Wellman, Cross, & Watson, 2001) found little evidence for a difference in children's responses on these questions, but did not investigate the weak effect size that was reported for the interaction between age and question type. The two meta-analyses reported here update the literature review, and find a more robust interaction between question type and age. Three-year-olds showed better performance on questions about their own representational change than others' false belief, while older children showed the reverse pattern. A mega-analysis of a sample of over 1200 children between the ages of 36–60 months then showed the same result. This response pattern requires novel theoretical interpretations, which include reframing the development of children's understanding of false belief.