Existing evidence suggests that children, when they first pass standard theory-of-mind tasks, still fail to understand the essential aspectuality of beliefs and other propositional attitudes: such attitudes refer to objects only under specific aspects. Oedipus, for example, believes Yocaste (his mother) is beautiful, but this does not imply that…

Three types of concepts were examined: concepts defined by sufficient features, concepts which possessed necessary and sufficient features, and concepts composed of exemplars with distinctive features. Second- and fifth-grade subjects learned the concepts in a procedure encouraging abstraction of common features or a procedure fostering exemplar…

Selected cognitive developments presumed to mediate the development of achievement motivation are described. Age trends for four causal schemes involving the concepts of effort and ability from 5 to 13 years of age are presented. Developments related to ability, task difficulty, and incentive value are also described. (Author/JMB)

Four- and five-year-old children were asked to compare the burning times of pairs of partially synchronous lights differing in intensity, bulb size, or both. (Author/MP)

Deals with (1) developmental changes in children's concepts of difficulty and ability and (2) individual differences within different developmental levels. Three levels of understanding of ability and difficulty are proposed, and cross-sectional and longitudinal evidence of progressive development through the stages is presented. (Author/RH)