It has been proposed that males would show higher mean scores than females in general intelligence ("g") because (1) men have, on average, larger brains than women, and (2) brain volume correlates with "g." Here we report a failure to support the conclusion derived from these premises. High resolution MRIs were acquired in a sample of one hundred…

Here we apply a method for automated segmentation of the hippocampus in 3D high-resolution structural brain MRI scans. One hundred and four healthy young adults completed twenty one tasks measuring abstract, verbal, and spatial intelligence, along with working memory, executive control, attention, and processing speed. After permutation tests…

In two experiments the neuronal mechanisms of sex differences in mental rotation were investigated. In Experiment 1 cortical activation was studied in women and men with similar levels of mental rotation ability (high, and average to low), who were equalized with respect to general intelligence. Sex difference in neuroelectric patterns of brain…

Sex differences in the latent general and broad cognitive abilities underlying the Differential Ability Scales, Second Edition were investigated for children and youth ages 5 through 17. Multi-group mean and covariance structural equation modeling was used to investigate sex differences in latent cognitive abilities as well as changes in these…

Allowing respondents to retake a cognitive ability test has shown to increase their test scores. Several theoretical models have been proposed to explain this effect, which make distinct assumptions regarding the measurement invariance of psychometric tests across test administration sessions with regard to narrower cognitive abilities and general…

Neuro-imaging studies of intelligence implicate the importance of a parietal-frontal network. One unresolved issue is whether this network underlies a general factor of intelligence ("g") or other specific cognitive factors. A second unresolved issue is whether males and females use different parts of this network. Here we obtained intelligence…

In three experiments, gender and ability (performance and emotional intelligence) related differences in brain activity--assessed with EEG methodology--while respondents were solving a spatial rotation tasks and identifying emotions in faces were investigated. The most robust gender related difference in brain activity was observed in the lower-2…

Sex differences in the latent general and broad abilities underlying the Kaufman Assessment Battery for Children-Second Edition (KABC-II) were investigated for children and youth ages 6 through 18. The data were split into different age groups to account for changes due to differential development. Multi-group higher-order analysis of mean and…

Sex differences in spatial ability are well documented, but poorly understood. In order to see whether working memory is an important factor in these differences, 50 males and 50 females performed tests of three-dimensional mental rotation and spatial visualization, along with tests of spatial and verbal working memory. Substantial differences…

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…

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.…

Current studies of cognition emphasize the contrast between two approaches to analysis of individual differences. It is concluded that the cognitive components approach incorporates the cognitive correlates approach, avoids the inadequacy of correlational methods, and models individual differences on various dimensions of cognitive functioning.…

The predictability of individual differences in the ability to reason about dynamic displays from tests using static displays was studied in 170 adults given paper-and-pencil and computer controlled tests. Several multivariate analyses indicated that the ability to reason about dynamic motion was distinct from the ability to reason about static…

When adult versions of tests of spatial ability were modified and administered to 94 boys and 99 girls in Norway, results indicated that spatial ability is a more unified trait in boys than in girls, in whom spatial abilities are more heterogeneously organized. (SLD)

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…