Argues that reasoning is not governed by mental logic or models. Proposes new operational semantic theory, in which reasoning is based on children's operational understanding of key terms in a given problem. Reports results of a study of class inclusion in which dramatic differences in performance were found as the result of linguistic context.…

First-, third-, and fifth-grade students saw matters involving intellectual conventions and personal preference as more variable across time and space than matters involving logic and physical laws. Furthermore, intellectual conventions were seen as legitimately changeable by social consensus and school authorities, but not on the basis of…

To assess the teachability of conditional logic structure, the commonly used syllogistic conditional reasoning task was divided into three main components: (1) inductive rule learning; (2) induction of conditional language; and (3) deductive interpretation. When trained on all components, fifth and seventh graders became very competent in dealing…