Dewayne, 19 months, is a very bright child who is responsive…

Dewayne, 19 months, is a very bright child who is responsive to his parents and to his grandmother who lives with his family. The child walked early and has an impressive receptive vocabulary. His older brothers, 8 and 10 are charmed with their little brother and play with him regularly. Wayne has developed a sense of object permanence, he realizes when his toy trucks are hidden under a blanket that they are not “gone.”  The child has a sense that objects take up space and that one thing follows another. He also is aware of the concept of causality, actions have specific consequences. For instance, when he pulls his dog, Milly’s ears, she runs away. Wayne no longer pulls the dogs ears. Piaget indicates that this child is in which stage of Sensory Motor Development?