The structure of Russians' life course has never been studied in depth; the only exception is demographic studies regarding marital status and age at childbirth. Principles that define life trajectories should also be examined. The "adult" concept is one of a number of important concepts in the general structure of life planning. This…

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…

Piaget's model of children's conceptual learning and development was compared with Klausmeier's Conceptual Learning and Development (CLD) model in a longitudinal study. The CLD model suggests four successive levels of concept learning: (1) concrete--recognizing an object which has been encountered previously; (2) identity--recognizing a known…