The role of introspection in children's developing theory of mind

Understanding sources of knowledge (e.g., seeing leads to knowing) is an important ability in young children’s theory of mind development. The research presented here measured if children were better at reporting their own versus another person’s knowledge states, which would indicate the presence of introspection. Children had to report when the person (self or other) had knowledge or ignorance after looking into one box and not looking into another box. In Study 1 (N = 66), 3- and 4-year-olds found the other-version of the task harder than the self-version whereas 5-year-olds performed near ceiling on both versions. This effect replicated in Study 2 (N = 43), which included familiarization trials to make sure children understood the question format. This finding is in support of the presence of introspection in preschool-aged children. In the same studies, children also showed evidence for theorizing about their own and others knowledge states in a guessing task (Study 1) and in true and false belief tasks (Study 2). These findings together indicate both introspection and theorizing are present during young children's theory of mind development.