The worst performance rule for cognitive tasks [Coyle, T.R. (2003). IQ, the worst performance rule, and Spearman's law: A reanalysis and extension. "Intelligence," 31, 567-587] in which reaction time is measured is the result that IQ scores correlate better with longer (i.e., 0.7 and 0.9 quantile) reaction times than shorter (i.e., 0.1 and 0.3…

The impurity of measures is considered as cause of erroneous interpretations of observed relationships. This paper concentrates on impurity with respect to the relationship between working memory and fluid intelligence. The means for the identification of impurity was the fixed-links model, which enabled the decomposition of variance into…

The aim of this study was to identify promising endophenotypes for intelligence in children and adolescents for future genetic studies in cognitive development. Based on the available set of endophenotypes for intelligence in adults, cognitive tasks were chosen covering the domains of working memory, processing speed, and selective attention. This…

Speed of information processing was examined in relation to fluid and crystallized intelligence in sixth graders. Reaction time parameters (except slope) were negatively correlated with scores on intelligence tasks. Partial correlations failed to support any causal relationship between fluid and crystallized intelligence in either direction.…

To clarify the relationships between reaction time (RT) variability and intelligence, RT distributions from 303 male Navy recruits were partitioned into 16 fast-to-slow latency bands calculated with measures of mental ability. The slowest bands (worst trials) were the best predictors of intelligence and working memory performance. (SLD)

The latency and amplitude of the P300, an event-related potential, during the performance of a memory-scanning task were used as indices of the efficiency of information processing that may mediate individual differences in intelligence. Results with 61 female college students contradict a pure speed of processing explanation of the relationship…

The genetic relationship between intelligence and components of cognition remains controversial. Conflicting results may be a function of the limited number of methods used in experimental evaluation. The current study is the first to use CANTAB (The Cambridge Neuropsychological Test Automated Battery). This is a battery of validated computerised…

Measures of verbal intelligence and abstract reasoning were taken on a group of 31 college-aged and 32 elderly adults, together with mental-processing rates associated with choice reaction time, primary memory scanning, and lexical decoding. Group means showed that verbal IQ and lexical decoding were intact in the elderly subjects. (Author/LMO)

The hypothesis that coping with novelty is a key aspect of intelligence is not supported by the data of Sternberg and Gastel. It is contended that these authors committed a common error by interpreting correlations involving difference scores without reference to the properties of the components of the difference. (SLD)

In two six-month longitudinal studies of intellectually advanced preschool children, letter naming time and background digit span were moderately good predictors of concurrent reading achievement, while no other standard cognitive indices, including mental age, were associated with reading achievement. Both memory span and retrieval were related…

This study is based on three distinct elementary cognitive tasks using chronometric techniques: (1) the S. Sternberg memory scan task, (2) a visual scan task; and (3) the Hick paradigm. Certain parameters of the tasks are compared experimentally and correlationally. Subjects were 48 university students, tested and retested on the tasks in a…

Several measures of the speed of information processing were related to ability factors derived from the Cattell-Horn theory of fluid and crystallized intelligence. Correlations among the ability measures, among the information processing measures, and between the two domains were analyzed using confirmatory factor analysis. (Author/PN)

The effects of controlling for individual differences in simple reaction time (RT) on the correlations of choice RT and discrimination RT with intelligence quotient were studied for 213 male college students. Simple RT was controlled by subtraction, partial correlation, and multiple correlation. (SLD)