Sex differences on the Attention Test (AC), the Raven's Standard Progressive Matrices (SPM), and the Brazilian Cognitive Battery (BPR5), were investigated using four large samples (total N=6780), residing in the states of Minas Gerais and Sao Paulo. The majority of samples used, which were obtained from educational settings, could be considered a…

Three prominent theories of intelligence, the Cattell-Horn-Carroll (CHC), extended fluid-crystallized (Gf-Gc) and verbal-perceptual-image rotation (VPR) theories, provide differing descriptions of the structure of intelligence (McGrew, 2009; Horn & Blankson, 2005; Johnson & Bouchard, 2005b). To compare these theories, models representing them were…

This study investigated the possibility that apparent sex differences in IQ are at least partly created by the degree of sample restriction from the baseline population. We used a nationally representative sample, the 1970 British Cohort Study. Sample sizes varied from 6518 to 11,389 between data-collection sweeps. Principal components analysis of…

The general differentiation hypothesis states that the strength of the correlations among a set of IQ subtests varies with a given variable. Instances of the general differentiation hypothesis that have been considered in the literature include age and ability differentiation. Traditionally, the differentiation effect is attributed to the varying…

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…

Recently, different methodological approaches have been discussed as an explanation for inconsistencies in studies investigating sex differences in different intelligences. The present study investigates sex differences in manifest sum scores, factor score estimates, and latent verbal, numerical, figural intelligence, as well as fluid and…

Various taxonomies of Raven's Advanced Progressive Matrices (APM) items have been proposed in the literature to account for performance on the test. In the present article, three such taxonomies based on information processing, namely Carpenter, Just and Shell's [Carpenter, P.A., Just, M.A., & Shell, P., (1990). What one intelligence test…

This study examines cultural bias in the Wechsler Intelligence Scale for Children. Results indicated no evidence of specific factors peculiar to Blacks v Whites, and rank order of item difficulties was similar in both groups. Race differences were due to differences in mental maturity rather than to test bias. (Author/RD)

A comparative factor analysis on intelligence data from four sex-by-generation groups was performed using the LISREL model. Spatial and verbal factors were isolated. Results were consistent with the hypothesis that males and females have similar intellectual structure. There were sex and generational differences in spatial and verbal factor means.…

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)

Fifteen cognitive abilities tests of the Hawaii Family Study of Cognition were factor analyzed concerning between-family means and within-family differences, using 370 sibling pairs of Americans of European ancestry and 116 sibling pairs of Japanese ancestry. The similarity of between-family and within-family structures suggests that the genetic…

Raven's Standard Progressive Matrices (SPM) was administered to a sample of 2735 12- to 18-year-olds in Estonia. Both a scree test and the consistent Akaike information criterion (CAIC) indicated the presence of three significant factors. Exploratory and confirmatory factor analysis showed the loadings of the items on the three factors, which were…

Most psychometric tests of spatial ability are paper-and-pencil tasks at the ''figural'' scale of space, in that they involve inspecting, imagining or mentally transforming small shapes or manipulable objects. Environmental spatial tasks, such as wayfinding or learning the layout of a building or city, are carried out in larger spaces that…