False beliefs or false positives? Limits on children's understanding of mental representation

We designed several modified false belief tasks to eliminate a confound present in the traditional tasks. The confound would allow children to answer correctly without reasoning about beliefs, by using a "perceptual access" approach to knowing in which they reason that a person who has not seen the true state of affairs will not know and will act incorrectly. The modified tasks incorporated 3 response alternatives (knowledge of the real state of affairs, the false belief, and an irrelevant or unjustified belief), and a yes-no question asked of each alternative. They included versions of the common Maxi, Smarties®, representational change, and appearance-reality tasks, plus a new ("plate") task. In 3 studies (N = 164), children at both 5 and 6 years performed substantially worse on modified tasks compared to traditional versions and gave perceptual access responses in addition to belief-based and reality-based responses. These findings call into question the validity of the traditional false belief task and suggest that more research employing a variety of methods is needed to determine the robustness of young children's understanding of beliefs.