Research was done to investigate the interfunctional relationships between a child's ability to order a set of objects and the development of language descriptives used to describe differing aspects of a group of objects which had been ordered. Results show that mean age of concrete operation acquisition is 7.1 years. (Author/JB)

This monograph reports the proceedings of a symposium that considered issues in the use of learning hierarchies in both psychological and educational research. The opening paper presents a brief overview of research on learning hierarchies. Issues considered include the use of behavior analysis as a basis for generating hierarchies, the extent to…

Research indicates that the brain grows in spurts occurring every two years or so and alternating with plateau periods in which the gains due to growth are consolidated. While the number of brain cells no longer increases after the age of about 18 months, substantial increases in the complexity of neural networks occur generally between the ages…