Extensive previous research has focused on the development of children's conceptual organization and its effects on children's veridical memory. The present research investigated whether the structure of children's category knowledge also affected their false memories using categorical lists in the DRM paradigm, a list-learning method commonly used in false memory research. In Experiment 1, the effects of graded category structure were examined with both third and sixth graders by accessing false memories for unstudied critical items of differing output dominance in category production. In Experiment 2, the effects of hierarchical category structure were examined with third graders by manipulating the hierarchical level of studied list items (basic or subordinate) and unstudied critical items (superordinate, basic, or subordinate). The results show that by age 10, the graded and hierarchical structure is present in children's conceptual organization and affects formation of false memories. Theoretical implications of the present findings are discussed.

Key words: category structure, false memory, list learning paradigm, memory development