Why children have difficulty reasoning with three-term series problems

This study examined a number of hypotheses as to why children have difficulty in solving three-term series problems. No support was found for the hypothesis that their difficulties arise because of their inability to understand transitive relations. In addition, the problems were present throughout the task, so that poor memory for the premises was ruled out as a contributory factor in reasoning difficulty. The children's performance was found to improve, however, when they were provided with an aid to reduce the demands of the task on working memory, although this advantage was not maintained in a later test without a memory aid. There was also evidence that, overall, the children had greater difficulty in solving problems that imposed a higher load on working memory.