From the monthly Saturday Review supplement, "Education in America, sponsored by the Charles F. Kettering Foundation.

Two studies examined modifiability in intellectual functioning in older adults. The fluid-crystallized theory provided a theory base for the research. (Fluid intelligence follows a normative decline through adulthood, while crystallized intelligence remains stable or even increases.) In the first study thirty subjects (average age 69.2)…

This paper discusses research exploring the performance factors involved in studies which test for formal operations. It is suggested that several previous studies dealing with formal operations confound performance and competence in determining the extent of subjects' formal operations schemata. Factors which might account for performance…

Areas of agreement and disagreement concerning intellectual developmental and the problems of mental retardation espoused by the author and by Uzgiris are discussed in this paper. The importance of environmental factors, along with the genetic and/or constitutional nature of the organism on which these environmental events impinge, is seen as…