Final answer:
The research by Baillargeon demonstrated that infants are able to reason about some characteristics of unseen objects.
Step-by-step explanation:
The research by Baillargeon examining infants' attention to a screen that rotated into the space occupied by hidden objects that were either tall or short demonstrated that infants are able to reason about some characteristics of unseen objects. Baillargeon's study showed that infants spent significantly more time looking at impossible events, indicating that they have an understanding of objects and how they work. This suggests that very young children have cognitive abilities beyond what Piaget believed and can infer information about hidden objects based on their previous experiences.