In, "Idiographic Filters for Psychological Constructs," Nesselroade, Gerstorf, Hardy, and Ram study patterns of variation within individuals. In this context they make an important suggestion: to test for invariant relations among latent variables, but to allow the relations between these latent variables and their indicators to vary between…

The construct of general intelligence is discussed in the context of factor models, differential validity of tests, Piagetian tasks, heritability, social class, and race. The general factor is an abstraction resulting from genes, environmental pressures, and neural structures involved in cognitive or intellectual human behavior. (Author/RD)

Relationships among Piagetian reasoning assessments and standard measures of intelligence and achievement were determined in 1972 by Stephens, McLaughlin, Miller, and Glass (EJ 055 112). The data were reanalyzed by Humphreys and Parsons in 1979 (EJ 218 642). In reply, Glass and Stephens note fallacies in Humphreys' and Parsons' reasoning.…

Stephens et al. (EJ 055 112) committed a serious methodological error in holding chronological age constant in their IQ measures and allowing it to vary in their Piagetian developmental measures. This error is unrelated to differences in factor rotation methods used by these authors and was not answered in their reply. (CTM)

These authors cite their own study of the relationship between traditional measures of intelligence and Piagetian measures of cognitive development in support of Glass and Stephens' contention that there are important qualitative differences. They question Humphreys' and Parsons' conclusions on both substantive and factor theoretical grounds. (CTM)