Two experiments investigated perceptual primacy of dimensional and similarity relations in stimulus classification of mentally retarded children. Results support a distinction between separable and integral stimulus structures, but do not support an integral-to-separable shift in perceptual development. Results suggest implications for…

A 10-step scale for assessing development of understanding relationships between honesty and kindness was developed and administered to 113 youths. Results indicated that development moved through 3 stages, as youths age 9-12 demonstrated abstract concepts of honesty and kindness; age 13-15 demonstrated simple abstract relations; and age 16-20…

In order to determine the cognitive development of Navajo children in terms of Piagetian conservation of number, mass, and continuous quantity, 168 Navajo children at seven different age levels from 5 to adult were presented with a series of three conservation tasks. The tasks consisted of a standard object and an equivalent object that could be…

The rationale and development of a new series of motion picture tests of perceptual abilities of young children are described, and preliminary data regarding their reliability and validity are presented. The data suggests that the film tests are promising new perceptual measurement instruments. (MS)