Tested the hypothesis that understanding of the pretend-real distinction develops earlier than understanding of the theoretically related apparent-real distinction. Found 3-year-old children consistently performed better on pretend-real tasks than on apparent-real tasks, even when the tasks were identical except for the distinction tested. (SKC)

Five studies examined adults' responses to weight conservation questions which were constructed to give subjects a choice of two incorrect answers. The results showed that adults (1) acquiesced to the misleading implications of the questions; and (2) exhibited greater nonconservation in response to questions about the body than about external…

Empirically describes the relative development of perceptual and conceptual understanding of left-right, back-front, up-down projective relationships between objects and provides a heuristic model of the cognitive processes involved in coordination of perspectives tasks. (Author/ED)

Tested the hypothesis that some attempts to reduce the performance demands of concrete Piagetian operational tasks may have allowed children to solve those tasks with preoperational functions. Administered two previously used versions of the transitivity task for length and weight to 120 children six- to nine-years-old. The second version was…

Administered five Piagetian tests to 180 adolescents for comparison to similar samples from 1967 and 1972. Found that today's adolescents exhibited higher levels of cognitive development than did previous cohorts. Gain varied across tasks, being very large for combinatory thought but mixed for conservation. This acceleration of cognitive…

Three longitudinal studies examined means-ends behavior of 6- to 8-month olds. Found that intentional means-end behavior increased between 6 and 7 months, with 7-month olds' performance influenced by the presence of a toy on the cloth. Performance was the same when cloth was attached to or separate from the toy. By 8 months, infants adjusted…

Three samples of 8- to 16-year olds were assessed three times at yearly intervals on eight water-level items. Within-child change over age was viewed as stochastic process of the child changing or remaining in one of three latent strategy states. Although there was improvement in task performance over age, the general finding was that strategy…

Investigated the general relationship between children's performance on social and physical measures of cognitive functioning, possible sex differences in performance on the two types of tasks, and the relationship between boys' and girls' performances on these tasks and age and IQ. (SDH)