Three experiments tested 3- and 4-year-olds' use of abstract principles to classify and label objects by shape or function. Findings indicated that 4-year-olds readily adopted either rule when instructed to match objects by shape or function, but 3-year-olds followed only the shape rule. Without a rule, 4-year-olds tended to match by shape unless…

Three experiments examined the role of representations in adolescents' deductive reasoning. Findings indicated that, with age, conditional reasoning improved on tasks containing permission conditional relations; reasoning fallacies increased on tasks containing causal conditional relations. Valid conditional inferences were more common on problems…

Tested with adolescents and adults two predictions from Markovits and Barrouillet's developmental model of conditional reasoning related to the effects of the association between antecedent and consequent terms and the formulation of the minor premise on uncertainty responses. Found results consistent with hypotheses and indicating importance of…

Two studies examined young children's ability to understand whether the actions of artifacts, insects, mammals, or humans were caused by mental or physical states. The studies suggest that children abstract specific features of action when construing its cause across disparate situations and actors. (MDM)

The Conceptual Learning and Development (CLD) Model specifies four levels of concept attainment (concrete, identity, classificatory, and formal) and three uses of concepts (problem solving, subordinate-supraordinate, and principles). Longitudinal and cross-sectional studies of concept attainment may be conducted. The results of this study of 300…