Cognitive Constraints on the Development of Hierarchical Spatial Organization Skills

This study examines the mechanism behind an observed shift in young children's hierarchical organization skills. By 9 years of age, children, like adults, code the location of an object in a homogeneous space at two levels (fine-grained and categorical) and combine this information when reporting location. For points within a circle, multi-level location coding occurs for both radius and angle. Before age 9 years, children employ hierarchical coding only radially. It was hypothesized that younger children may either be unable to encode and/or process two dimensions simultaneously, or to impose the frame of reference required for angular subdivision. Tasks were designed to test these two hypotheses: one reduced the relevant dimensions required for coding, the other provided the frame of reference. Results indicate that 7-year-olds are able to form angular categories when the number of dimensions for coding is reduced, and that an explicit frame of reference does not facilitate mature angular category division. The acquisition of adult forms of spatial representation appears to be limited by encoding and/or processing capacities, rather than by spatial abilities.