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)

This paper summarizes empirical findings of research on a theory of general mental ability, based on laboratory studies of the relationship between measurements of individual differences on conventional psychometric tests and in speed and efficiency of information processes. The paper covers characteristics of "g" (general mental ability),…

Longitudinal data on the auditory forward and backward digit span (FDS and BDS) subtests of the Wechsler Intelligence Scale for Children (WISC) were obtained at five age levels (between 6 and 13), in samples of white and black children. Factor analysis and analysis of variance of the data were conducted to test 5 hypotheses, related to Jensen's…

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 contribution of heredity to scores on a digit span intelligence test, Jensen's Memory for Numbers, was estimated with a standard heritability formula. The test measures level I mental ability--the capacity to store and recall, but not ability to elaborate or manipulate stimuli. Subjects were 35 monozygotic (MZ) twins and 35 same-sex dizygotic…

The two-factor theory proposed concerns familial mental retardation, in which retardation is mild (IQ 50-70) and persons appear clinically normal with no signs of neurological damage. It is stated that persons in this IQ range differ greatly in vocational, social, and other non-scholastic abilities, and that these differences are only slightly…

Based on a paper presented at the American Educational Research Association Convention (Annual, Chicago, Illinois, February 8, 1968).

In a study in which Asian-American, white, and black children in grades 2-6 in a California school district were given a battery of tests including measures of IQ, scholastic achievement, and short-term memory, factor analysis of the tests yielded two main factors identified as Level I (memory) and Level II (general intelligence) in Jensen's…

An explanation is sought for the striking apparent failure of the interactions of intelligence and memory factors with socioeconomic status predicted by Jensen's Level I/Level II theory, in a study by Stankov, Horn and Roy (EJ 239 630). It is suggested that Level I ability is a category of narrower abilities involving rote learning and primary…

This book focuses on topics germane to cognitive abilities viewed from a "minority psychology" perspective. The most contentious chapters concern test bias and heredity, with culture, socioeconomic status, and case viewed as the chief explanations for test score differences between social classes and racial and ethnic groups. The reviewer…

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 report contains a series of studies which represent ongoing research of six investigators, who seek to elucidate through empirical studies the psychological characteristics of culturally disadvantaged children. The chief aim has been to make comparative analyses of abilities and learning characteristics of children from intact subpopulation…