Examined the assumption that Spearman's law acts unsystematically and approximately uniformly for various subtests of cognitive ability in an IQ test battery when high- and low-ability IQ groups are selected. Data from national standardization samples for Wechsler adult and child IQ tests affirm regularities in Spearman's "Law of Diminishing…

Psychometric g is by far more highly correlated with all tests conventionally called "IQ," cognitive abilities, and the like, than any other single factor or combination of other factors independent of g. Researchers must now examine the nature of psychometric g, including its causal underpinnings. (LMO)

Data from a previous adoption study using the Wechsler Intelligence Scale for Children-Revised show that the genetic effect is reflected by psychometric "g" (general intelligence) to a greater degree than is the environmental effect. This finding is consistent with the hypothesis that "g" largely reflects the genetic component…

A large number of national and geographic population samples were used to test the hypothesis that the variation in mean values of skin color in the diverse populations are consistently correlated with the mean measured or estimated IQs of the various groups, as are some other physical variables, known as an ecological correlation. Straightforward…

The author examines claims that the Kaufman Assessment Battery for Children (K-ABC) is less culturally biased than other standard tests of intelligence. He concludes that the diminished Black-White difference for the K-ABC is largely the result of psychometric and statistical artifacts. Implications for future test construction are noted.…

This study investigated whether a unitary elemental process or several independent processes underlie psychometric "g" (factor of general intelligence). Results with 101 college students administered 2 intelligence tests and a large battery of elementary cognitive tasks suggest that as many as 4 independent components make up…

The author presents intelligence and learning as theoretically and empirically separate concepts. Examining Spearman's "g" factor and the evolution, phylogeny and psychometrics of intelligence, he concludes that "g" is of dominant importance in scholastic learning. He notes some implications for equal educational opportunity.…

This commentary on a paper by Douglas Detterman and others (EC 604 995), on assessing basic cognitive abilities in young adults with and without mental retardation, argues that variables measuring correct responding and variables measuring response latency or speed are two aspects of the same underlying continuum of speed and efficiency of…

The stability of psychometric "g," the general factor of intelligence, is investigated in simulated correlation matrices and in typical empirical data from a large battery of mental tests. "G" is robust and almost invariant across methods of analysis. A reasonable strategy for estimating "g" is suggested. (SLD)

The hypothetical idea of a perfectly pure psychometric "g" is empirically unattainable. Because the unity of "g" cannot be proved or disproved by factor analysis, the unitary "g" hypothesis represents a parsimonious assumption. J. B. Carroll's (1991) analysis demonstrates the relationship between psychometric and…

Results from a battery of 17 diverse tests completed by 877 white and 855 black students in grades 3 through 8 support Spearman's hypothesis that the white-black difference in test performance is predominantly a general intelligence ("g") difference rather than a unitary developmental difference affecting all factors in test performance.…

Information processing was measured in terms of reaction time and movement time to stimulus displays which differed in amount of information transmitted. Only reaction time increased as a linear function of number of bits in the stimulus display. Both show individual differences which significantly correlated with intelligence. (Author/RD)

Groups of 270 Black and 270 White children drawn from the national stratified random sample used in the standardization of the Wechsler Intelligence Scale for Children-Revised (WISC-R) were matched on age, sex, and WISC-R Full-Scale Intelligence Quotient to facilitate investigation of the patterns of specific cognitive abilities. (Author)

The Ramey and Haskins intervention experiment is examined. Narrow transfer of training from cognitive intervention techniques to IQ test performance in early childhood, rather than enhancement of the g factor itself, is hypothesized as a cause of the typical fadeout of early IQ gains in later childhood. (Author/RD)

Measurements derived from reaction time, movement time, and an index of neural adaptability derived from averaged evoked potentials are significantly related to each other as well as to g factor scores extracted from a battery of 15 psychometric tests in a sample of 54 severely retarded adults. (Author/RD)