Recent work suggests that infants rely on mechanisms of object-based attention and short-term memory to represent small numbers of objects. Such work shows that infants discriminate arrays containing 1, 2, or 3 objects, but fail with arrays greater than 3 [Feigenson, L., & Carey, S. (2003). Tracking individuals via object-files: Evidence from…

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…