A secular decline in the strength of Spearman’s g in Japan

It has been found in the United States and in Scotland that the subtests of the WISC-R and WAIS-R are more highly intercorrelated among low-intelligence groups than among high. The value of the intercorrelations is a measure of the strength of Spearman’s g, and hence Spearman’s g is apparently stronger among populations with low intelligence. Since intelligence has been increasing over time, it should follow that the strength of g has shown a corresponding decline. Evidence from the standardization samples of the WISC and WISC-R in Japan shows that this is the case.     

Body Composition And Human Sleep

It has been reported that fit atheletes have more slow wave sleep (SWS), sleep longer and have shorter sleep onset latencies than unfit individuals. However, we have shown that these differences are not a direct consequence of physical fitness. This suggests that the effect is due to more enduring characteristics of individuals. We report two experiments designed to test the hypothesis that individual differences in sleep are related to differences in body composition. The hypothesis was tested in two different experiments, each comparing independent groups of fit athletes with unfit non-athletes. In each experiment both sleep and a number of anthropometric variables were measured. Twenty-five fit and 22 unfit subjects were run in Experiment 1 and 17 fit and 17 unfit in Experiment 2. In Experiment 1 percentage fat was estimated from a skin fold method, while in Experiment 2 lean body mass (LBM) was estimated from 24 h. urinary creatinine. The results showed that percentage LBM was negatively related to SWS in fit subjects, while the amount of LBM and weight were negatively related in the unfit groups. When all subjects were combined within each experiment, significant negative correlations were found between SWS and both LBM and percentage LBM in Experiment 2. The results suggest that body composition influences SWS levels, but not other components of sleep.     

Response latency and response accuracy as measures of memory

The relationship is examined between response accuracy and response latency as measures of memory, and questions are raised concerning the value of the unidimensionality assumption often invoked in theories of memory. Three paired-associate experiments investigated the effects of the length of the retention interval, the kind of processing during incidental learning, and the number of study versus test trials during intentional learning. The findings, together with a review of selected studies in the literature, support three conclusions: (1) Latency of correct recall is not necessarily more sensitive than accuracy, (2) accuracy and latency of correct recall measure different aspects of memory, and (3) latency of correct recall and latency of incorrect recall measure different aspects of memory. The available data disconfirm the idea that any unidimensional construct (such as strength or the amount of information in memory) underlies memory performance. An explanation is offered that emphasizes the distinction between encoding and retrieval processes.     

A construct validation of the Objective-Analytic Test Battery (OATB)

The scales of Cattell's Objective–Analytic Test Battery (OATB) and the factors derived from the factor analysis of the subtests of the OATB were located with respect to a wide range of ability and personality variables, including the 16PF and Cattell's Comprehensive Ability Battery. The expected relationships between the OATB scales and the personality measures did not emerge. However, it was found that many of the OATB scales were highly correlated with ability factors. It is concluded that in Britain, and in its present form, the OATB is not a viable instrument for measuring personality traits.     

EEG alpha asymmetry and creativity

Results of 3 experiments examining the relationship between creativity and left-hemisphere and right-hemisphere EEG activity are reported. Creativity has been hypothesized to involve the use of primary-process cognition, and such cognition is hypothetically accompanied by activation of the right cerebral hemisphere. In light of these hypotheses, we predicted that highly-creative people should exhibit greater right-hemisphere than left-hemisphere EEG activity during creative performance and that this pattern would not be found in less-creative people. All 3 experiments supported this prediction. This difference in asymmetry was specific to creative performance. It was not present during basal recordings or during a non-creative task.