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…

To explore the possible neural foundations of individual differences in intelligence test scores, we examined the associations between Raven's Matrices scores and two tasks that were administered in a functional magnetic resonance imaging (fMRI) setting. The two tasks were an n-back working memory (N = 37) task and inspection time (N = 47). The…

We evaluated over 200 participants semiannually from 12 to 48 months of age on measures of intellectual (Bayley Scales, Stanford-Binet Scale) and verbal (MacArthur-Bates Inventory, Peabody Picture Vocabulary Test) status. Structural equation modeling and hierarchical linear (growth curve) analyses were applied to address the nature of development…

This study explores whether or not intelligence tests' scores predict individual differences in scholastic achievement irrespective of SES factors such parents' income and education. The variables of interest are analyzed considering three independent samples of participants comprising a total of 641 children. The participants belonged to a…

The Zahlen-Verbindungs-Test (ZVT) represents a highly feasible measure of information-processing speed that correlates quite highly with standard psychometric tests of intelligence. The present study was designed to identify specific stages of the sensorimotor processing system that may account for individual differences in overall variability of…

Studied the associations between scores on a test of general mental ability and reaction time, measured with a "Hick"-style device, using a sample of 900 adults (aged 56 years) in Scotland. Results agree with literature reviews suggesting that reaction times and their variabilities are stronger correlates of mental test scores than are…

Tested 101 adults, aged 77, who had completed psychometric intelligence testing in 1932, with the same test of mental ability. Results of this study, the longest follow-up study reported to date, show substantial stability in mental ability differences from childhood to late life. (SLD)

Age differences in intellect as reflected in performance on the revised Wechsler Adult Intelligence Scale (WAIS-R) from age 20 to 74 years were evaluated for 1,480 adults from the WAIS-R standardization sample, while educational levels were held constant. Implications of the results for intelligence testing are discussed. (SLD)

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…

Taking into account various models and findings pertaining to the nature of analogical reasoning, this study explored quantitative and qualitative individual differences in intelligence using latency and eye-movement data. Fifty-five university students were administered 14 selected items of the Raven's Advanced Progressive Matrices test. Results…

A new analysis of data from 15 cognitive tasks completed by 93 subjects with scores on the Cattell Culture Fair test show that differences in Cattell score systematically affected performance on some tasks more than on others. Implications for theories of local and global differences in mental ability are discussed. (SLD)

Sternberg and Gastel have provided an example of a major principle of intelligence research--the relationship between a task's working memory demands and its sensitivity to individual differences in fluid intelligence and "g." There is no need to invoke additional constructs such as "novelty." (SLD)

Four points are made in regard to the controversial reaction times studies: (1) apparatus used is not the best; (2) practice effects have not been thoroughly accounted for; (3) there is some evidence that simple reactions are different from choice ones; and (4) basic data to be explained are those which show substantial group differences.…

Whether relations between intelligence test performance and information processing measures depend on individual differences in speed-accuracy preferences rather than capacity limitations and whether the impact of strategic variables changes with increasing age or extraversion was studied with 83 adults ages 50 to 79 years. Results are discussed…

The relationship between psychometric intelligence and reaction times (RT) was studied in 60 undergraduates using an elementary cognitive task, the Sentence-Picture Verification Test. Results, which show that psychometric intelligence is substantially correlated with RTs even after practice, support the mental speed hypothesis of general…