Young Children's Copying of Block Constructions: Significant Constraints in a Highly Complex Task

Block construction is ubiquitous in early development, yet is surprisingly complex, involving stepby-step sequenced actions to create specific structures. Here, we use novel analytic methods to characterize these action sequences in detail, including which individual parts of the structure ('states') are built and how these structures are combined, creating a fully specified build path towards the final structure. We find that, like adults tested in a previous study, 4- to 8-year-olds build by creating a small subset of possible individual states and full build paths, and that they prioritize building layer-by-layer. The individual states and build paths that children produce are strikingly similar to those of adults, resulting in structures that are more stable than other possible (but not attested) states and paths. Our approach serves as a lens into the cognitive processes underlying block building and suggests that children's building is guided by significant cognitive constraints consistent with computational thinking.