Early Understanding of Mental Entities: A Reexamination of Childhood Realism

Real physical objects (e.g., a chair) can be distinguished from mental entities (e.g., a thought about a chair) on the basis of a number of criteria. 3 of these are behavioral-sensory evidence--whether the entity can be seen, touched, and physically acted upon; public existence--whether other persons experience the entity; and consistent existence--whether the entity consistently exists over time. Two studies tested 3-5-year-old children's ability to distinguish real versus mental entities on the basis of these criteria and to categorize such entities suitably. Even 3-year-olds were able to judge real and mental entities appropriately on the basis of the 3 criteria, to sort such entities as explicitly real and not-real, and to provide cogent explanations of their choices as well. A further distinction between real and mental entities is that mental entities can be about physically impossible, nonexistent things (e.g., a dog that flies). A third study demonstrated that 3-5-year-olds also appreciated this distinction. Taken together, these results contradict a common characterization of the young child as unaware of the fundamental ontological distinction between the internal mental world and objective reality. The implications of these findings are discussed for 3 other bodies of research: Piaget's characterization of young children as realists, Keil's theory of ontological development, and recent research on children's understanding of the mind.