Rising verbal intelligence scores: implications for research and clinical practice

Evidence suggests that scores on various intelligence tests have been rising at a fast rate. To find out whether performance on the Wechsler Adult Intelligence Scale (WAIS) Vocabulary subtest has also been rising, the authors searched major psychology journals for investigations involving healthy younger and older adult participants and collected the reported WAIS Vocabulary scores. The meta-analysis shows that WAIS Vocabulary scores have been rising at the rate of 0.117/year (corresponding to 1.52 IQ points/decade) for younger adults and 0.367/year (corresponding to 4.79 IQ points/decade) for older adults.     

II. The comparability of the WISC-R and WAIS among 16-year-old EMR children

Thirty 16-year-old EMR children were administered the WAIS and WISC-R in counterbalance order to determine the comparability of the two assessment instruments. The WAIS was found to yield significantly higher Verbal, Performance, and Full Scale IQ scores. The comparisons of corresponding subtests indicate that all WAIS subtests were significantly higher than the WISC-R except Picture Completion. Correlations between corresponding WAIS and WISC-R IQ scales and subtests, however, were significant. The results suggest differences between the two instruments among children of subnormal intelligence, thus presenting the possibility that a child may be differentially classified based on the selection of the intelligence test.     

Intelligence as measured by the WAIS and a military draft board group test

Intelligence test scores derived from individual administration of the WAIS and group administration of a military draft board screening test were obtained for a sample of 232 young Danish males. The means on both tests show the sample was somewhat above the Danish average. Despite a more than four-year time interval between the two testings, and procedural and content differences between the tests themselves, the correlation between the two test scores was substantial (0.82). Consequently, we conclude that the group administered draft board test measures the same general intelligence as does the individually administered WAIS and is therefore well suited to large-scale epidemiological and demographic studies of intelligence.     

Testing the indifferentiation hypothesis during childhood, adolescence, and adulthood

The general (g) factor is the most general and relevant cognitive ability. This factor is considered to be one of the most important predictors of academic achievement and of many other socially relevant behavioral outcomes. In the last decades, many researchers have investigated the possible changes in the relevance of the g factor from childhood to adulthood. The indifferentiation hypothesis states that the variance attributed to the g factor and the main cognitive abilities will not change over the life span. In the present study, the authors tested that hypothesis in childhood, adolescence, and adulthood by using 2 different cognitive batteries (Test of Educational Ability [TEA; S. A. TEA, 1999], Wechsler Adult Intelligence Scales [WAIS; D. Wechsler, 1955]), which they administered in 2 different countries--Spain (TEA) and the United States (WAIS). The ages of the participants (N = 2,384) ranged from 8 to 54 years. Results showed that the number of factors extracted and the relevance were the same for every age group in both batteries, as predicted by the indifferentiation hypothesis. The authors discuss implications of intelligence assessment.     

Covariates of Production and Perseveration on Tests of Phonemic,Semantic and Alternating Fluency in Normal Aging

ABSTRACT

Standard measures of phonemic and semantic fluency, as well as fluency measures that impose additional demands upon set-switching were administered to younger and older adults. No age effect was found for total output on semantic fluency, while older participants generated significantly more responses relative to their younger counterparts on the phonemic measure. However, older adults made significantly more perseverative errors on both these measures. For tests of alternating fluency, only where participants were required to switch between two semantic dimensions, was an age deficit observed. Although the correlation between phonemic repetitions and age remained significant when performance on the Digit Symbol Test or a measure of fluid intelligence was partialled out, age effects for semantic repetitions and semantic alternating fluency were substantially reduced. The age benefit for number of correct responses upon phonemic fluency was significantly attenuated when a measure of crystallized intelligence was entered as a control variable. The theoretical and practical implications of these results are discussed.     

Effects of age and the relationship between response time measures and psychometric intelligence in younger adults

The major goal of the present study was to investigate the potential influence of age on the relationship among performance measures derived from a Hick reaction time task and general intelligence (psychometric g). Participants were 130 male and 130 female younger adults (mean age: 24.6 years) covering a wide range of individual levels of intelligence. Results from structural-equation modelling analyses clearly indicate that there is no evidence for the notion of a general speed factor underlying psychometric g. A much more sufficient model is provided by the assumption that median reaction time (RTmd) and intraindividual variability of reaction time (RTSD), though highly correlated, reflect two distinct sources of variance for psychometric g. While age was negatively associated with RTmd, no such relationship could be established for RTSD.     

IQ stability: the relation between child and young adult intelligence test scores in low-birthweight samples

The stability of IQ from childhood to adulthood in low-birthweight subjects was measured in two independent samples with follow-up intervals of approximately 14 and 9.5 years. In both samples, intelligence was assessed with the WISC at a mean age of 9.5. Twenty-six subjects were retested with the WAIS at a mean age of 23.5, and 78 subjects with the BPP (the Danish Military Draft Board Intelligence Test) at the age of 19.1. Both samples obtained childhood and adult test scores below the expected means. For the Wechsler Verbal, Performance and Full-Scale IQs, the stability quotients were 0.86, 0.86, and 0.89 in the WAIS sample, and the retest correlations for the three IQs with the BPP score were 0.66, 0.65, and 0.74. Thus, the majority of children showed stable patterns of intellectual development from middle childhood to young adulthood.     

Age differences,cerebral arousability,and human intelligence

This report describes an empirical test of the cerebral arousability theory of intelligence which predicts that EEG-intelligence correlations will vary systematically as a function of age-related changes in cerebral arousal. Data were obtained from 76 subjects, in six different age-groups, with equal numbers of males and females in each group. AEP measures evaluated the amplitude, frequency and variability of EEG responses evoked by auditory stimulation. In accordance with arousability theory, but in contrast to an earlier report by D.E. Hendrickson (1982), the results show that there is no simple linear relationship between any of the EEG measures and general intelligence. There is a predicted increase in cerebral arousal during early adulthood with the highest arousal found for the 41–50 age-group and thereafter a steady decline with increasing age. Positive and negative Pearson product-moment correlations were found for variation of cerebral arousal with respect to WAIS ‘verbal’ and ‘spatial’ scores, respectively. These correlations conform exactly to the pattern predicted from arousability theory. Also, as expected from theory, the correlations for the youngest and oldest age-groups were generally greater in magnitude and more likely to be statistically significant with values ranging up to r = 0.78.     

Covariates of production and perseveration on tests of phonemic, semantic and alternating fluency in normal aging

Standard measures of phonemic and semantic fluency, as well as fluency measures that impose additional demands upon set-switching were administered to younger and older adults. No age effect was found for total output on semantic fluency, while older participants generated significantly more responses relative to their younger counterparts on the phonemic measure. However, older adults made significantly more perseverative errors on both these measures. For tests of alternating fluency, only where participants were required to switch between two semantic dimensions, was an age deficit observed. Although the correlation between phonemic repetitions and age remained significant when performance on the Digit Symbol Test or a measure of fluid intelligence was partialled out, age effects for semantic repetitions and semantic alternating fluency were substantially reduced. The age benefit for number of correct responses upon phonemic fluency was significantly attenuated when a measure of crystallized intelligence was entered as a control variable. The theoretical and practical implications of these results are discussed.     

Analysis of variances and covariances is misleading as a guide to a common factor model

The “factor” analyses published by Schultz, Kaye, and Hoyer (1980) confused component and factor analysis and led in this case as in many others to unwarranted conclusions. They used component analysis to develop factor models that were subjected to restricted (confirmatory) maximum likelihood analysis, but the final models for which good fits with the observed correlations were obtained were not common factor models. They were, however, discussed as such and conclusions drawn accordingly. When their correlation matrices are analyzed by the principal factors method, two factors are sufficient to account for the intercorrelations. These two factors generally support the a priori expectation of a difference between intelligence tasks and spontaneous flexibility tasks. They are also quite similar in younger and older subjects, when similarity is judged in terms of factor pattern. Factor loadings for the younger subjects, however, are much smaller than expectations based on the respective ranges of talent in the two groups of subjects or on past experience with similar tests in undergraduate student populations.     

How personality relates to intelligence test performance: Implications for a theory of intelligence,ageing research and personality assessment

Previously reported findings indicate that variation of EEG evoked potential parameters is strongly related to both personality and intelligence differences (Robinson, 1982a, b). These data and the associated theory imply that personality should relate to intelligence test performance. Results are described in this report which indicate that subtest profiles obtained with the Wechsler Adult Intelligence Scale (WAIS) differ significantly for Ss scoring highest and lowest on the Extraversion (E) scale of the Eysenck Personality Questionnaire (EPQ); introverts tend to do better on the ‘Verbal’ subtests while extraverts tend to do better on the ‘Performance’ measures. Ss with middling scores on the E scale of the EPQ can also be distinguished in terms of specific WAIS profiles. In this case the results define two contrasting groups. Young male Ss with middling E scores tend to have high Psychoticism (P) and low Lie (L) scores on the EPQ as well as having distinctive WAIS profiles characterized by higher scores on subtests normally associated with a ‘Memory’ or ‘Attention-Concentration’ factor. Higher scores were also obtained by this subgroup on the Picture Arrangement and Block Design subtests which were previously shown to load a P + /L ? factor. The converse is true for older female Ss who also have middling E scores. As well as demonstrating a systematic relationship between personality and intelligence test performance these data provide some further support for a model of brain-behaviour relationships proposed by Robinson. Within this theoretical framework a neurophysiologically meaningful explanation can be provided for the three major factors that reliably emerge in factor-analytic studies of the WAIS. From an applied viewpoint, the data indicate that personality differences can be assessed from performance on tests such as the WAIS. On this issue the results are discussed with particular reference to Gittinger's Personality Assessment System. Implications for ageing research are also discussed.     

Comparative relationships of the Wechsler Adult Intelligence Scale—Revised (WAIS-R) and the Wechsler Adult Intelligence Scale (WAIS) to the Wechsler Memory Scale (WMS)

This study investigated whether the Wechsler Adult Intelligence Scale — Revised (WAIS-R) and Wechsler Adult Intelligence Scale (WAIS) demonstrate similar patterns of relationship with the Wechsler Memory Scale (WMS). Sixty VA patients were administered the WAIS-R and WMS and 60 completed the WAIS and WMS. The groups were comparable in terms of demographic variables. Pearson correlations were computed between the subtest and IQ scores from the intelligence scales and the scores from the WMS for each group. Comparison of the resulting correlations for the WAIS-R group with those of the WAIS subjects demonstrated only four significant differences, indicating that the WAIS-R and WAIS variables covary in a similar manner with the WMS scores. Following factor analysis of the test data for both groups, coefficients of congruence indicated a high degree of similarity between the two factor solutions. Essentially the same relationships emerged between intelligence variables and the WMS regardless of which scale was administered.     

Fluid and crystallized intelligence: effects of diffuse brain damage on the WAIS

In the 1940's two forms of intelligence, fluid and crystallized, were postulated. Active mental processing (WAIS performance subtests) were fluid while well learned abilities (WAIS verbal subtests) were crystallized. Brain damage was considered to affect fluid abilities more than crystallized. WAIS scores comparing normal and diffusely organically damaged subjects indicated that, as hypothesized, the verbal subtests were more affected than the performance subtests.     

Are age-related changes in cognitive function driven by age-related changes in sensory processing?

Although there has been keen interest in the association among measures of sensory function and cognitive function for many years, in general, measures of sensory function have been confined to one or two senses and measures of threshold sensitivity (acuity). In this study, rigorous psychophysical measures of threshold sensitivity, temporal gap detection, temporal order identification, and temporal masking have been obtained, in hearing, vision, and touch. In addition, all subjects completed 15 subtests of the Wechsler Adult Intelligence Scale, 3rd edition (WAIS–III). Data were obtained from 245 adults (18–87 years old) for the WAIS–III and for 40 measures of threshold sensitivity and temporal processing. The focus in this report is on individual differences in performance for the entire data set. Principal-components (PC) factor analysis reduced the 40 psychophysical measures to eight correlated factors, which were reduced further to a single global sensory processing factor. Similarly, PC factor analysis of the 15 WAIS–III scores resulted in three correlated factors that were further reduced to a single global cognitive function factor. Age, global sensory processing, and global cognitive function were all moderately and significantly correlated with one another. However, paired partial correlations, controlling for the third of these three measures, revealed that the moderate correlation between age and global cognitive function went to zero when global sensory processing was controlled for; the other two partial correlations remained intact. Structural models confirmed this result. These analyses suggest that the long-standing observation of age-related changes in cognitive function may be mediated by age-related changes in global sensory processing.     

Synesthesia and creativity in fine arts students: An Empirical Look

Abstract:

A survey of 358 fine arts students at three large universities indicated that 23% (84) experienced synesthesia in a spontaneous and consistent manner, and 49% (175) reported no such experience. From this subject pool, 61 synesthetes and 61 controls, equated on gender, major, year in school, and verbal intelligence, received a battery of four creativity measures. The synesthetes scored significantly higher than controls on all four creativity measures; and their self‐rated frequency and vividness of synesthesia though significantly intercorrelated, correlated marginally with the measures of creativity. The results are consistent with anecdotal reports that synesthetes are often involved in musical and artistic fields, and possessive of a high degree of creativity.     

Correlations of measures of personality and of intelligence within and across generations

Members of over 100 families were administered the Wechsler Adult Intelligence Scale (WAIS) as well as various psychometric tests of personality. Individual cognitive and personality measures often were associated. Parent personality scale scores often were associated with offspring WAIS scores and vice versa. Stepwise multiple regressions demonstrated that knowledge of parental personality test scores substantially increased the predictability of offspring WAIS scores.     

Creativity,Mood Disorders,and Emotional Intelligence

The study addressed two findings in the creativity literature that show, on the one hand, that bipolar disorder and other clinical dysfunctions are overrepresented among eminently creative people, and that positive affect is positively associated with creativity. The central hypothesis of the study was that emotional intelligence could be an intervening variable between clinical conditions and creative production. A sample of 412 undergraduates completed a wide range of divergent thinking and creative production measures, and the Emotional Intelligence Scale; 11 percent of the sample reported that they had completed treatment for mood disorder and 5 percent report that they were currently in treatment. A combination of regression and ANOVA analyses revealed: The link between mood disorders and creative production persisted after emotional intelligence was statistically removed; the same was true for ideational fluency and flexibility of cognitive style. The link between emotional intelligence and creative production persisted after the effect of clinical disorders was removed. Ideational fluency and emotional intelligence were higher among people who completed treatment compared to people in treatment. The tentative interpretation is that emotional intelligence serves as a counterweight against mood disorders in enhancing creative production.     

Extent of psychological differentiation and creativity.

Among the extensive array of studies relating Witkin's construct of psychological differentiation to many psychological functions and variables, none seem to have adequately tested its relationship to creativity, although these two variables have personality traits and development characteristics in common and require similar skills for effective performance. Eighty-five male high school students were separated according to Embedded Figures Test, and the extreme groups tested for creativity by eight factorially pure tests developed by Guilford, and by Schaefer and Anastasi's Biographical Inventory. Statistical procedures included analysis of covariance, analysis of variance, and a matrix of intercorrelations. With intelligence controlled, field-independent persons performed significantly better than field-dependent persons on measures of visualization, spontaneous flexibility, adaptive flexibility, and creativity in mathematics and science but not significantly better on the other six creativity tests.     

A revalidation of the Thurstone Test of Mental Alertness as a brief measure of intelligence through comparison with the Wechsler Adult Intelligence Scale-III

In earlier research, Rossini, Wygonik, Barrett, and Friedman (1994) demonstrated that the Thurstone Test of Mental Alertness (TMA) is a valid, brief measure of intelligence by comparing it to the Wechsler Scale of Adult Intelligence-Revised, which was at that time the "gold standard" of IQ assessment. Since that study, the WAIS has again been revised and reissued in a third edition, the WAIS-III. We assessed the relationship between scores on the Thurstone Test of Mental Alertness and this latest WAIS test to see if there is still a predictive relationship between the two tests. Correlations between the two tests and the accuracy of TMA point estimates of IQ indicate that the Thurstone Test of Mental Alertness remains a viable brief measure of adult intelligence.     

Factors predicting the use of technology: findings from the Center for Research and Education on Aging and Technology Enhancement (CREATE)

The successful adoption of technology is becoming increasingly important to functional independence. The present article reports findings from the Center for Research and Education on Aging and Technology Enhancement (CREATE) on the use of technology among community-dwelling adults. The sample included 1,204 individuals ranging in age from 18-91 years. All participants completed a battery that included measures of demographic characteristics, self-rated health, experience with technology, attitudes toward computers, and component cognitive abilities. Findings indicate that the older adults were less likely than younger adults to use technology in general, computers, and the World Wide Web. The results also indicate that computer anxiety, fluid intelligence, and crystallized intelligence were important predictors of the use of technology. The relationship between age and adoption of technology was mediated by cognitive abilities, computer self-efficacy, and computer anxiety. These findings are discussed in terms of training strategies to promote technology adoption.