Spearman's law of diminishing returns (SLODR) posits that at higher levels of general cognitive ability the general factor ("g") performs less well in explaining individual differences in cognitive test performance. Research has generally supported SLODR, but previous research has required the a priori division of respondents into…

Researchers interested in working memory have debated whether it should be considered a single latent cognitive ability or a set of essentially independent latent abilities distinguished by domain-specific memory and/or processing resources. Simultaneously, researchers interested in cognitive aging have established that there are substantial…

This study was designed to test the reliability of five major models of the structure of cognitive abilities. A battery of 16 tests was administered to 1000 Swedish sixth graders. Based on the results, a three-level hierarchical LISREL-based model (the HILI-model) is suggested. (Author/EGS)

This study examined whether a timesharing factor can be identified when a number of competing tasks are presented in the midst of a range of single tests designed to sample a broad range of psychological dimensions. A battery of single and competing tasks was presented to 126 subjects. (Author/LMO)

Members of 118 families were administered the Wechsler Adult Intelligence Scale; a cognitive test battery; and tests of visual, auditory, and figure memory. Factor analysis of memory scores resulted in four-factor solution. Significant spouse correlations and significant midparent-midchild regressions were found for some of the memory measures.…

A reanalysis of Stephens' intercorrelations of Wechsler subtests, achievement tests, and Piagetian tasks was conducted. (EJ 055 112) Piagetian tasks contributed almost equally to the definition of the general factor in intelligence along with the Wechsler subtests and the achievement tests. Communality outweighed differences between intelligence…

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)

The author refutes Humphrey's test of the Spearman hypothesis. A fair test requires that Black and White samples not be selected on any g-correlated variable, including socioeconomic status. Humphrey's factor analysis on test-score means of demographic groups, rather than on individuals, inflates g loadings and biases results. (LMO)

This author reviews published data and presents new data relevant to the Spearman hypothesis concerning racial differences on cognitive tests. He concludes that across-the-board difference between SES groups occurs primarily on the general factor, and that there are major determinants of race differences independent of the general factor.…

The author responds to criticisms made by Jensen pertaining to tests of the Spearman hypothesis. The near-zero correlation between Blacks and low socio-economic status Whites is neither an artifact of methodology nor a sampling fluke. Low and high SES White differences are highly correlated with general factor loadings. (LMO)