Proceedings of the Annual Meeting of the Cognitive Science Society

Even infants have a remarkably sophisticated understanding of objects, agents, and how they interact. We investi-gated young children’s ability to reason about the relationship between complexity of physical structures created by agents, theirperceived difficulty, and the time required for creating these structures. Seventy 4-5 year-olds were shown trials consisting ofpairs of agents who had the same numbers of blocks but made different structures (e.g., horizontal line vs. vertical tower, castlestructure vs. two piles of blocks). Children were asked which structure was easier to make (Difficulty condition) or who wasdone first (Time condition). Even the youngest participants were successful in determining which structure is more difficult,but their estimates of time showed improvement with age. These results offer novel insights into how an early understanding ofdifficulty and time shape young children’s beliefs about how agents intervene on the physical world to induce changes in theirstates.