Studied whether genetic variability explained some of the variance in coincidence timing and whether common genetic factors accounted for the association with intellectual functioning using 55 pairs of 16-year-old twins. Results suggest that the genetic influence operating on coincidence timing skills was of similar magnitude to that of response…

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…

The relation between general intelligence (psychometric "g") and temporal resolution capacity of the central nervous system was examined by assessing performance on eight different temporal tasks in a sample of 100 participants. Correlational and principal component analyses suggested a unitary timing mechanism, referred to as temporal "g".…

We examined autonomic physiological responses induced by six different cognitive ability tasks, varying in complexity, that were selected on the basis of on Guilford's Structure of Intellect model. In a group of 52 participants, task performance was measured together with nine different autonomic response measures and respiration rate. Weighted…

Jensen has reported reaction-time (RT) studies indicating that various parameters correlate significantly with IQ. Two parameters of interest are slope of RT across set size and increasing correlations of RT with IQ as set size increases. After reviewing these studies, the author concludes that Jensen's claims are unwarranted. (Author/BW)

Tested 133 college students in Germany with new tasks and 6 working memory marker tasks. Results reveal three working memory functions: simultaneous storage and processing; supervision; and coordination of elements into structures. Each function could be subdivided into distinct components of variance. (SLD)

Whether IQ level exerts a differential effect on the impairment of cognitive performance induced during acute hypoglycemia was studied for 24 nondiabetic adults. At various levels of hypoglycemia, no overall effect of IQ on deterioration was noted. Higher IQ did not apparently protect against adverse effects. (SLD)

The dendritic structure of layer II-III pyramidal neurons of the parietal cortex in 41 Long-Evans rats was compared to behavioral assessments of attention to novelty, response flexibility, and reasoning. A significant correlation between dendritic arborization and behavioral performance was not demonstrated. (SLD)

Used the classical twin design with 390 pairs of twins to study the influence of genetic factors on the large phenotypic variation in inspection time (IT) and whether the well-established IT-IQ association could be explained by a common genetic factor. Findings provide potentially important information for the biological bases of the…

Two experiments involving 45 and 48 undergraduate students, one introducing a same-different letter discrimination tasks and the other exploring the effects of practice on inspection time (IT), suggest that at least one component of mental speed that is sensitive to practice may be an important factor underlying the correlation between IT and IQ.…

The purpose of this study is to meta-analyze the published studies that measure the performance differences in mental chronometric tasks using a behavioral genetic research design. Because chronometric tasks are so simple, individual differences in the time it takes to complete them are largely due to underlying biological and physiological…

Young adults, originally tested as infants for their ability to process information as measured by selective attention to novelty (an operational definition of visual recognition memory), were revisited. A current estimate of IQ was obtained as well as a measure of academic achievement. Information processing ability at 6-12 months was predictive…

The General Strategies Hypothesis and the Strategy-deficiency Hypothesis are discussed in relation to conclusions made by Symposium participants. A contrast emerges between Borkowski, et. al.'s embrace of the Strategy-deficiency Hypothesis and Turnure's dissatisfaction with it. (LMO)

Cluster analysis, applied to Carroll's cognitive theory, indicates that the obtained clusters make intuitive sense and imply that taxonomy is possible. Moreover, some clusters are similar to those suggested by other theories, especially the theory of fluid and crystallized intelligence. (Author/CP)

The first purpose of this editorial is to indicate a parallel trend in two disparate areas of research: information processing and cognitive-behavior modification (CBM). The second purpose is to highlight the role that affect plays in intellectual functioning, noting implications following the assessment of intelligence. (Author/RD)