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.     

Thought Disorder on the WAIS-R Relative to the Rorschach: Assessing Identity-Disordered Adolescents

Clinical researchers have noted that compared with other diagnostic groups, adults with Borderline Personality Disorder tend to demonstrate relatively more thought disorder on unstructured projective tests (e.g., Rorschach) than on structured objective tests of cognitive performance (e.g., Wechsler Adult Intelligence Scale; WAIS). Using archival data, our study found evidence that adolescents with Identity Disorder tend to exhibit this same phenomenon. The records of 62 adolescent inpatients who had been administered the WAIS or WAIS-R and the Rorschach were examined. Of the 62 cases, 25 were diagnosed with Identity Disorder, 14 with Conduct Disorder (Group Type), 15 with Oppositional Defiant Disorder, and 8 with Schizophreniform Disorder. For each participant, the WAIS or WAIS-R and the Rorschach were scored according to the Thought Disorder Index (TDI; Johnston & Holzman). Adolescents with Identity Disorder revealed a significantly larger discrepancy between TDI scores on the WAIS or WAIS-R and TDI scores on the Rorschach than did adolescents with other diagnoses. The findings suggested that the discrepancy between the degree of thought disorder on structured versus unstructured psychological tests (i.e., differential decompensation) is related to diagnosis.     

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.     

Ethnic group-by-generation interactions in WAIS scores in the Hawaii family study of cognition

This paper is a comparatively small-scale replication of a paper by DeFries, Corley, Johnson, Vandenberg, & Wilson (1982), using that subset of the DeFries subject group that was administered the Wechsler Adult Intelligence Scale (WAIS) and comparing parent vs. offspring performance of Americans of European and of Japanese Ancestry. Like DeFries et al., significant ethnic group-by-generation interactions were obtained in WAIS scores, suggesting the existence of substantial cultural influences on cognitive-test performance.     

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.     

Patterns of Perceptual and Motor Organization

Previous research has suggested that the Pauker (1963) and Satz and Mogul (1962) short forms of the WAIS have beenefficaciousinestimating the standard form. While there is a growing need in correctional settings for quicker evaluation procedures, the lack of WAIS short form research with prisoners prohibits their use with such populations, Hence, this study employed 126 youngadult male inmates to test the corn parability of the above cited short forms and the standard WAIS across a variety of evaluative criteria. The results generally suggested the superiority of the Pauker (1963) form in estimating the standard WAIS. However, because the current study employed only black and white young male offenders it is suggested that the current findings not be generalized to other age groups, races, or women inmates until these findings are cross-validated on such samples.     

Comparability of WAIS and WAIS--R scores among mentally retarded adults

This study compared the performance on the WAIS and WAIS--R of 21 mentally retarded adults residing in an Intermediate Care Facility. Tests were administered in one order, the WAIS initially and the WAIS--R second, with approximately two years between testings. Significant differences were found on the WAIS and WAIS--R for Verbal, Performance and Full Scale IQs. This finding contrasts with the differences between the measures as reported in the WAIS--R manual.     

Structure of Witkin's Embedded Figures Test

A number of reports have indicated that Witkin's Embedded Figures Test correlates with performance on standard intelligence tests. This finding was replicated in a recent factor analytic study when the test loaded substantially on a factor best representing the performance subtests of the Wechsler Adult Intelligence Scale (WAIS). However, the embedded figures also loaded on an uncorrelated factor, in addition to those normally associated with WAIS, which would relate well to Witkin's conception of psychological differentiation. These loadings on two uncorrelated factors suggested that the factorial structure of the Embedded Figures Test should be examined. An item analysis indicated a bi-factorial structure and, as presently constituted, the scale will provide misleading and ambiguous information.     

Properties of the diffuse thalamocortical system, human intelligence and differentiated vs integrated modes of learning

In complementary reports Robinson (1982a, b) describes how the transmission characteristics or time constants of thalamic and cortical neuron populations of the diffuse thalamocortical system (DTS) can be evaluated in human subjects. Equating these constants with the Pavlovian property of ‘strength’ it was predicted that they should relate to Extraversion and Neuroticism scores on the Eysenck Personality Questionnaire (EPQ). This prediction was confirmed and the results provide direct support for the theories of Pavlov and Eysenck. The present report describes additional results which confirm predictions relating the DTS constants to performance on the Wechsler Adult Intelligence Scale (WAIS) and on the Embedded Figures Test (EFT). An important finding was that a measure of deviation from intermediate and ‘balanced’ values of the DTS constants loads to the extent of -0.80 on the WAIS ‘memory’ or ‘attention/ concentration’ factor. More generally, the results provide further support for Pavlov's conception of brain-behaviour relationships and suggest that the DTS plays a fundamental role in determining a broad spectrum of human psychological differences including some associated with the concepts of intelligence and cognitive style. These IQ and cognitive style differences are explained as the immediate and longer-term consequences, respectively, of differences in the distribution of background cortical activity mediated by the DTS.     

Development of an automated performance test system for environmental and behavioral toxicology studies

In developing a menu of computerized performance tests for repeated-measures applications the metric properties of selected tests have been examined. Factors of chief concern have been stability and reliability, as well as the practical issue of the length of time it takes to achieve high levels of both. In this study, these factors, as well as predictive validity, are examined. 25 subjects were tested repeatedly (10 sessions) with 11 tests previously identified as "good" candidates for repeated-measures research in paper-and-pencil (marker test) versions. The 11 tests were administered concurrently in their traditional paper-and-pencil modes and newly implemented microcomputer-based versions, along with the Wechsler Adult Intelligence Scale (WAIS). Nine of the 11 microcomputer-based tests achieved stability. Reliabilities were generally high, with r greater than or equal to .77 for 3 min. of testing. Cross-correlations of microbased tests with traditional paper-and-pencil versions suggest equivalency between the test constructs in the different media. Correlations between six of the microbased subtests and the WAIS identified common variance, and these might comprise an efficient short (6 min.) battery of tests.     

Need for achievement and performance on measures of behavioral fluency.

This investigation was designed to assess the relationship between a validated personality characteristic, need for achievement (nAch), and performance on measures of behavioral fluency. To infer this relationship, 50 neurologically intact college undergraduates were administered a questionnaire assessing nAch and a battery of tests including a short form of the WAIS and measures of behavioral fluency (i.e., verbal fluency). Statistical analysis indicated that subjects high on nAch obtained higher scores than subjects low on nAch on the measures of figural fluency and the WAIS Verbal Scale. No significant difference on verbal fluency was seen between the two groups. Secondly, the group high on nAch also had a higher mean Verbal IQ but not a higher mean Performance IQ as measured by a short form of the WAIS than did subjects scoring low on nAch.     

The effects of haloperidol on thought disorder and IQ in schizophrenia

The impact of haloperidol treatment on the Wechsler Adult Intelligence Scale (WAIS) and the Thought Disorder Index was investigated in a group of 19 patients with schizophrenia tested both before and after 26 days of treatment with haloperidol. Thought disorder scores declined significantly over the course of treatment and fewer patients demonstrated severe forms of thought disorder at the end of the trial. WAIS performance improved significantly but the magnitude of change was consistent with the literature on expected practice effects. Thought disorder scores were negatively correlated with IQ at baseline, but not at Day 26. The results suggest a partial dissociation of thought disorder and other cognitive functions in schizophrenia.     

The Effects of Haloperidol on Thought Disorder and IQ in Schizophrenia

The impact of haloperidol treatment on the Wechsler Adult intelligence Scale (WAIS) and the Thought Disorder Index was investigated in a group of 19 patients with schizophrenia tested both before and after 26 days of treatment with haloperidol. Thought disorder scores declined significantly over the course of treatment and fewer patients demonstrated severe forms of thought disorder at the end of the trial. WAIS performance improved significantly but the magnitude of change was consistent with the literature on expected practice effects. Thought disorder scores were negatively correlated with IQ at baseline, but not at Day 26. The results suggest a partial dissociation of thought disorder and other cognitive functions in schizophrenia.     

Further analyses of the effects of practice,dropout, sex,socio-economic advantage,and recruitment cohort differences during the University of Manchester longitudinal study of cognitive change in old age

A sample of 4,314 volunteers who, when first recruited, were aged from 41 to 93 years were quadrennially tested from 2 to 4 occasions during the next 4 to 20 years on the Cattell Culture Fair intelligence test, 2 tests of information-processing speed, the Wechsler Adult Intelligence Scale (WAIS) vocabulary test, and 3 memory tests. After significant effects of practice, sex, demographics, socio-economic advantage, and recruitment cohort had been identified and considered, performance on all tests declined with age. These age-related declines accelerated for the Cattell and WAIS, 2 tests of information speed, and 2 of the memory tests. For all tests individuals' trajectories of age-related change diverged with increasing age but, unexpectedly, were not affected by demographic factors. Practice gains from an initial experience of the cognitive tests remained undiminished as the interval before the second experience increased from 4 to 8 + years.     

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.     

Stanford-Binet and WAIS IQ differences and their implications for adults with intellectual disability (aka mental retardation)

Stanford-Binet and Wechsler Adult Intelligence Scale (WAIS) IQs were compared for a group of 74 adults with intellectual disability (ID). In every case, WAIS Full Scale IQ was higher than the Stanford-Binet Composite IQ, with a mean difference of 16.7 points. These differences did not appear to be due to the lower minimum possible score for the Stanford-Binet. Additional comparisons with other measures suggested that the WAIS might systematically underestimate severity of intellectual impairment. Implications of these findings are discussed regarding determination of disability status, estimating prevalence of ID, assessing dementia and aging-related cognitive declines, and diagnosis of ID in forensic cases involving a possible death penalty.     

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.     

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.     

The Psychosexual Identification of Preschool Boys

It was hypothesized that increases in level of arousal should lead to improvement in the performance of intellectual tasks and to decrements in the performance of creative tasks because of the effect of drive level on range of cue utilization and availability of remote associates. Subjects were given the Remote Associates Test (RAT) and a version of the WAIS Similarities subtest under low arousal (relaxed), medium arousal (stress), and high arousal (white noise) conditions. Trends were as predicted, but reached acceptable levels of significance only for the effects of high arousal on creative performance. Evidence for the validity of the RAT was provided by the finding that RAT and intellectual performance are affected in opposite ways by the same experimental manipulations. It is suggested that flexibility in changing level of arousal may be a determinant of both creativity and intelligence and that this common trait may explain the tendency of tests of the the two to correlate.     

Complex Reaction Time and General Intelligence: A Refinement

College students (N = 28) completed a reaction-time task that yielded decision times for simple and complex conditions. Each student was also administered the revised edition of the Wechsler Adult Intelligence Scales (WAIS-R). Decision-time parameters generally correlated negatively with WAIS subscales. These correlations reached significance, however, mainly with timed performance subscales. The results were consistent with Vernon's (1983) results.