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…

Studied whether a primary imagery (IM) factor can be identified as a separate dimension of individual differences in the spatial ability domain. Findings for 213 adults suggest the existence of three first-order IM factors, and a second-order confirmatory factor analysis suggests that the visual imagery dimensions can be located within the spatial…

To explore the relationship between spatial ability and both image quality and image process efficiency, 79 subjects completed spatial tests, imagery questionnaires, and laboratory tasks. Laboratory measures of process efficiency and image quality were strongly related to spatial test performance and weakly related to one another. (Author/BW)

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…

Because they used an inappropriate statistical procedure, J. H. Kranzler and A. R. Jensen (1991) have not demonstrated that a factor of general intelligence ("g") depends on several independent factors. A factorial reanalysis of their data suggests that speed and efficiency of information processing are important in "g." (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…

In their reply to the present author's critique (1991), J. H. Kranzler and A. R. Jensen have still not demonstrated that a factor of general intelligence, "g," depends on, or contains, several independent factors. They have only demonstrated that an estimate of "g" is predictable from several independent components. (SLD)

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…

Scores on ability tests given to 1,274 students in grades 4-6 and 1,310 in grades 7-9 were simultaneously factor analyzed at class and individual levels. At the individual level, the general factor was most highly loaded on fluid abilities. Three common factors were established at the class level. (SLD)