抄録
This study examined when children are able to solve conditional reasoning problems correctly using the thinking strategy that spontaneously retrieves alternatives based on the inclusive/hierarchical relations of categories and how the strategy changes with aging. In the experiment, a total of 210 3-, 4-, 5-, 8-, 10-, 12-years-old, and adults were given the conditional reasoning problems and were also asked to justify their judgments. The result showed that 5-year-old children could solve the problems as well as the adults and they used the strategy similar to the adults, but the strategy did not necessarily continue to be used from children to adults.
