In one form of category-based induction, people make predictions about unknown properties of objects. There is a tension between predictions made based on the object's specific features (e.g., objects above a certain size tend not to fly) and those made by reference to category-level knowledge (e.g., birds fly). Seven experiments with artificial…

In four parts, this discussion describes characteristics of the thought of infants, preschool children, primary school students, and adolescents. Topics briefly addressed in part I, on the thought processes/capabilities of babies, concern sensorimotor thought without abstraction, the importance of physical exploration, the development of…