The present longitudinal multi-cohort study examines whether interindividual variability in cognitive performance and change increases in old age, and whether associations among developments of different cognitive functions increase with adult age. Multivariate multiple-group latent growth modeling was applied to data from narrow cohorts separated…

Derived changes in genes associated with primary microcephaly (MCPH) have been suggested to be "currently sweeping to fixation" i.e., increasing in frequency in most populations, with the likely outcome that the derived allele will completely displace the ancestral allele over time. Possible causes for this sweep include effects on human reasoning…

Sex differences in the latent general and broad cognitive abilities underlying the Woodcock-Johnson Tests of Cognitive Abilities were investigated for children, youth, and adults ages 6 through 59. A developmental, multiple indicator-multiple cause, structural equation model was used to investigate sex differences in latent cognitive abilities as…

A hierarchical factor solution was obtained from a psychometrized battery of Piagetian-type tasks individually administered to 660 kindergarten children. The first two levels of factors included Piagetian theoretical entities. A third level factor was identified as a g. The association of Piagetian tasks with academic achievement was through the g…

Raven's Progressive Matrices test items were analyzed for M demand (Pascual-Leone's developmental construct). Data on second- and third-grade subjects were analyzed for extent of absolute agreement of Raven and Figural Intersection Test (FIT) scores. Raw scores on the Raven could be deduced on the basis of FIT performance. (Author/RD)

Whether "psychometric" and "Piagetian" kinds of intelligence are similar is a question of whether they have similar courses of development with age. When using factor analysis to address this issue, age effects must be eliminated in order to assess relations among measured constructs. Reanalyses of previous results were…

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.…

Change in cognitive functioning is an important aspect of human aging and a key outcome in many medical conditions. However, cognitive change can rarely be measured directly, since prior cognitive data do not exist for most people. We examined the criterion validity and one-year stability of the difference between National Adult Reading Test…

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)