Wechsler Adult Intelligence Scale-Revised Standardization Research Articles

Factor analytic support for social cognition as a separable cognitive domain in schizophrenia

Social cognition has received increasing attention in schizophrenia due to its theoretical relevance to core features of the disorder as well as the marked deficits in social functioning exhibited by these patients. However, there remains a need to develop and validate measures of social cognitive abilities and to demonstrate that they are constructs that are separable from non-social neurocognitive processes. In the current study, the Wechsler Adult Intelligence Scale-Revised (WAIS-R) was administered to 169 males with schizophrenia, and test results were subjected to confirmatory factor analysis (CFA) to determine if those WAIS-R subtests containing social content would form a distinct Social Cognition (SC) factor. CFA was used to evaluate various models that hypothesized an SC factor, and for comparison purposes the same models were evaluated in the WAIS-R standardization sample. Results confirmed the presence of a four-factor model that included an SC factor, as well as the more commonly reported Verbal Comprehension, Perceptual Organization, and Working Memory factors. The SC factor consisted of the Picture Arrangement and Picture Completion subtests, and demonstrated small but significant correlations with disorganization and negative symptoms, as well as with an index of social functioning. Results provide support for the validity of the SC factor as a measure of social cognition in schizophrenia, and demonstrate that at least some aspects of social cognition represent separable cognitive domains in schizophrenia.

Revisiting the Factor Structure of the WAIS-R

Past attempts to model via confirmatory factor analysis (CFA) the Wechsler Adult Intelligence Scale-Revised (WAIS-R) intersubtest covariation have used an oblique factor or a higher order modeling approach. The attempts have failed to yield adequate model fit, based on current CFA recommendations. Using the WAIS-R standardization data, it is demonstrated that the WAIS-R can be better conceptualized as measuring a first-order general factor and three orthogonal group-level factors. The results are discussed in relation to Verbal and Performance Intelligence scoring and failed attempts to find relationships between VIQ/PIQ difference scores and external criteria. Because Arithmetic and Digit Span did not share any variance with the other VIQ subtests, independent of General Intelligence, clinicians should reconsider interpreting a VIQ score that includes information from Arithmetic and Digit Span in nonclinical populations. Researchers are encouraged to model intelligence factors as nested factor models, considering their superior model fit, and the increased clarity in the interpretations of relationships between IQ indices and criteria.

Base rates of WAIS-R VIQ-PIQ differences in 1593 psychiatric inpatients.

The purpose of this study was to provide the psychologist with base-rate tables for the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Verbal IQ-Performance IQ difference scores in 1593 psychiatric inpatients. Subtables also were provided for each of three primary psychiatric diagnoses (schizophrenia spectrum disorders, bipolar disorders, and depression). The base rates of VIQ-PIQ splits in the full inpatient sample, and those for the subsamples based on primary psychiatric diagnosis, were very similar to those reported in the WAIS-R standardization sample. Consistent with past research on the standardization sample, the VIQ-PIQ split was correlated positively with Full Scale IQ (FSIQ), indicating that larger splits are more common at the higher IQ levels. Therefore, base-rate tables also were provided for the total inpatient sample split into five IQ groupings.

Confirmatory factor analysis of the WAIS-R in patients with schizophrenia

Although factor scores are commonly used to interpret the Wechsler Adult Intelligence Scale—Revised (WAIS-R), the WAIS-R factor structure has not been investigated in patients with schizophrenia. We used confirmatory factor analysis (CFA) to examine five latent construct models in 169 males with schizophrenia. The WAIS-R standardization sample (ages 35–44; n=250) was used as a comparison group. For both groups, all model fit indexes used to determine model adequacy supported models composed of Verbal Comprehension (VC), Perceptual Organization (PO) and Freedom from Distractibility (FFD) factors. However, the Digit Symbol subtest loaded on both the PO and FFD factors for patients with schizophrenia but only on the FFD factor for the WAIS-R standardization sample. Patients with schizophrenia performed significantly worse on the FFD and PO factors compared to the VC factor, reflecting the well-characterized attention and problem solving deficits associated with schizophrenia. Also, patients with schizophrenia performed significantly worse than the WAIS-R sample on all factors. These results provide support for the validity of the WAIS-R factors in patients with schizophrenia.

Intersubtest scatter on the Wechsler Adult Intelligence Scale—Revised for China: Reply to Li and Balfour (1996).

In reply to the W. Li and L. Balfour (1996) critique of our study Intersubtest scatter on the Mainland Chinese version of the Wechsler Adult Intelligence Scale (J. J. Ryan, X. Y. Dai, & A. M. Paolo, 1992), some minor omissions in the original article are clarified and additional data are presented. The major conclusion from the 1992 article is substantiated via generalization to other samples. Thus, among Chinese adults and adolescents who experienced the Great Cultural Revolution, education and IQ were highly correlated, and intersubtest scatter decreased as intelligence level increased. The latter finding is contrary to that for Americans in the Wechsler Adult Intelligence Scale-Revised standardization sample, who demonstrated increased scatter as the magnitude of the Full Scale IQ increased (J. E. McLean, A. S. Kaufman, & C. R. Reynolds, 1989).

Intersubtest scatter on the Wechsler Adult Intelligence Scale--Revised for China: Reply to Li and Balfour (1996).

In reply to the W. Li and L. Balfour (1996) critique of our study Intersubtest scatter on the Mainland Chinese version of the Wechsler Adult Intelligence Scale (J. J. Ryan, X. Y. Dai, & A. M. Paolo, 1992), some minor omissions in the original article are clarified and additional data are presented. The major conclusion from the 1992 article is substantiated via generalization to other samples. Thus, among Chinese adults and adolescents who experienced the Great Cultural Revolution, education and IQ were highly correlated, and intersubtest scatter decreased as intelligence level increased. The latter finding is contrary to that for Americans in the Wechsler Adult Intelligence Scale-Revised standardization sample, who demonstrated increased scatter as the magnitude of the Full Scale IQ increased (J. E. McLean, A. S. Kaufman, & C. R. Reynolds, 1989).

Aging, brain size and IQ

Brain size and certain aspects of intellectual functioning, in particular nonverbal, perceptual-motor abilities as measured by the Performance Intellectual Quotient (PIQ) of the Wechsler Adult Intelligence Scale-Revised (WAIS-R), decline with age. This investigation examined whether cross-sectional rates of decline for brain volume and PIQ were equivalent over the years 16–65. Whole brain volume changes determined by magnetic resonance (MR) imaging techniques, were based on normative data presented by Blatter et al. (1995). PIQ sums of scaled scores were from the WAIS-R standardization sample as analyzed by Kaufman et al. (1991). Results of univariate regression analyses indicate remarkably similar rates of decline. The potential relationships between magnetic resonance (MR) identified anatomic atrophic changes in whole brain volume and perceptual-motor decline associated with age is discussed.

Neurodiagnostic implications of abnormal verbal-performance IQ discrepancies on the WAIS-R: A comparison with the standardization sample

The neurodiagnostic value of Wechsler Adult Intelligence Scale-Revised (WAIS-R) Verbal-Performance IQ (VIQ-PIQ) discrepancies was evaluated in a brain-damaged sample. The VIQ-PIQ differences of 260 neurologically impaired patients was compared to the WAIS-R standardization sample. The average VIQ-PIQ discrepancy of the patients was significantly larger than the mean IQ difference for normals. Comparison of the number of subjects whose VIQ-PIQ discrepancy equaled or exceeded 95% of the controls revealed no differences for the total sample and for individuals with low average or average intelligence. Conversely, the frequency of abnormal VIQ-PIQ differences was significantly greater among patients with Full Scale IQs <or= 79. The occurrence of an abnormal VIQ-PIQ discrepancy in persons with IQs <or= 79 should serve as a stimulus for further assessment.

Neurodiagnostic implications of abnormal verbal-performance IQ discrepancies on the WAIS-R: A comparison with the standardization sample

The neurodiagnostic value of Wechsler Adult Intelligence Scale-Revised (WAIS-R) Verbal-Performance IQ (VIQ-PIQ) discrepancies was evaluated in a brain-damaged sample. The VIQ-PIQ differences of 260 neurologically impaired patients was compared to the WAIS-R standardization sample. The average VIQ-PIQ discrepancy of the patients was significantly larger than the mean IQ difference for normals. Comparison of the number of subjects whose VIQ-PIQ discrepancy equaled or exceeded 95% of the controls revealed no differences for the total sample and for individuals with low average or average intelligence. Conversely, the frequency of abnormal VIQ-PIQ differences was significantly greater among patients with Full Scale IQs ≤ 79. The occurrence of an abnormal VIQ-PIQ discrepancy in persons with IQs ≤ 79 should serve as a stimulus for further assessment.

Validation of Kaufman, Ishikuma, and Kaufman-Packer's Wechsler Adult Intelligence Scale--Revised short forms on a clinical sample.

Short forms of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) developed by A. Kaufman, T. Ishikuma, and J. Kaufman-Packer (1991) were cross-validated on 207 male and 133 female psychiatric inpatients and outpatients (aged 16-79 years) with low mean IQ. Results showed that the short forms displayed psychometric properties comparable to those observed in the WAIS-R standardization sample. Validities were stable across differences in S age, gender, race, inpatient versus outpatient status, years of education, and diagnosis. In contrast to D. Boone's (1992a) findings, the 4-subtest short form evidenced greater predictive accuracy than either the 2- or the 3-subtest form. Users are cautioned that it is inappropriate to classify individuals according to level of intelligence on the basis of short-form IQ scores

WAIS—R abbreviated forms in the elderly: A comparison of the Satz-Mogel with a seven-subtest short form.

The Satz-Mogel abbreviation of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) was compared with a 7-subtest short form (Ward, 1990) in samples of normal and neurologically impaired elderly persons 75 years and older. The normals were 130 subjects from the old-age WAIS-R standardization sample, and the brain-damaged group consisted of 40 men with medically diagnosed brain dysfunction averaging 79.57 (SD = 5.4) years of age. The short forms were highly similar in administration times, correlations with the WAIS-R IQs (all rs >.92), estimation of the average IQ scores, and in classification of intelligence for both the normal and neurologically impaired subjects. Finally, both short forms correctly estimated significant Verbal IQ-Performance IQ discrepancies about 75% of the time

Base rates of intersubtest scatter in the old age standardization sample of the WAIS-R

The Wechsler Adult Intelligence Scale-Revised (WAIS-R) old-age standardization sample was analyzed to ascertain normal base rates of intersubtest scatter. The range and number of scaled scores that deviated by +/- 3 points from the mean were calculated for each subject on the Verbal, Performance, and Full Scale subtests. Mean ranges for the total sample were 4.4, 3.4, and 6.5, respectively. Ranges were larger for men than women; whites demonstrated more scatter than blacks. An increase in scatter emerged on the Verbal and Full Scales as one moved from the lowest to the highest education and IQ groups. Over 75% of individuals had two, one, or zero subtests that deviated significantly from their WAIS-R mean score. Finally, the scatter range for the elderly sample was compared to the original WAIS-R standardization sample.

Inter-subtest scatter in the WAIS-R standardization sample

To be able to evaluate the possible diagnostic significance of the magnitude of subtest-to-subtest scatter on the Wechsler Adult Intelligence Scale—Revised (WAIS-R), it is important to know the frequency of various levels of scatter in the general population. To provide this information, the magnitude of scatter across all 11 subtests, and across the subtests of the Verbal and Performance scales, was computed for each of the 1,880 individuals used in the WAIS-R standardization. The range (difference between highest and lowest subtest scaled scores) was found to be an effective measure of scatter when compared with other, more complex indices. Scaled score scatter, which ranged from 2 to 16 points on the Full Scale, averaged 6.7 points for the Full Scale and 4.7 points each for the Verbal and Performance scales. Scatter had little relationship to age, sex, race, and years of education completed. However, the average amount of scatter increased substantially with IQ level. Normative tables for interpreting scatter are provided, and implications of these findings for the practitioner, especially in neuropsychology, are discussed.

Demographic characteristics and IQ among adults: Analysis of the WAIS-R standardization sample as a function of the stratification variables

The goal of the present investigation was to analyze data from the standardization sample of the 1981 Wechsler Adult Intelligence Scale-Revised (WAIS-R) to determine the relationships of WAIS-R IQs to the demographic variables upon which the sample was stratified. The sample included 1, 880 adults stratified according to sex and age (equal numbers of males and females within nine groups), race, occupation, urban-rural residence, geographic region, and education. There were 1, 664 whites, 192 blacks, and 24 from other nonwhite groups. Analyses of variance were conducted separately for Verbal (VIQ), Performance (PIQ), and Full Scale IQ (FSIQ). The differences in mean IQs due to sex, urban-rural residence, and geographic regions were nonsignificant. However, there were significant differences that were due to race and education level, and there were also sizeable differences noted for occupational groups. There was a 14 1 2 -point difference in favor of whites over blacks on FSIQ. Differences due to education and occupation were striking: College graduates earned FSIQs that were 32 1 2 points higher than the FSIQs of individuals with 7 years or less of schooling, and professional and technical workers outscored unskilled workers on the WAIS-R Full Scale by 22 points.

Verbal IQ vs. performance IQ difference scores in males and females from the WAIS-R standardization sample

Clinical research that has used the Wechsler-Bellevue and Wechsler Adult Intelligence Scales with patients who are suffering lateralized cerebral pathology had indicated distinct patterns of VIQ-PIQ discrepancies related to laterality of hemispheric involvement. Research data also have been interpreted to suggest that VIQ-PIQ discrepancy patterns differ as a function of the sex of the patient. However, this latter hypothesis finds less support in recent studies that have employed the newer Wechsler Adult Intelligence Scale-Revised (WAIS-R). This raises the possibility that, other than sex, manifest differences in VIQ-PIQ discrepancies may be more a consequence of normative characteristics in successive editions of the Wechsler scales or of other factors that surround neurologic impairment. Moreover, to date, clinical and research evidence for biologic sex as a mediating factor in VIQ-PIQ discrepancies has been interpreted in the absence of base rates for the distribution of such discrepancies, which occur in the normal population. Thus, the present study reports base rates for the magnitude, frequency, and direction of VIQ-PIQ discrepancies found for the 940 males and 940 females who comprise the WAIS-R standardization sample. No differences of consequence were noted in male vs. female VIQ-PIQ discrepancies. Implications are discussed in the light of earlier and emergent research with the Wechsler scales.

Factor structure of the WAIS-R for an incarcerated population

The factor structure of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) for a large sample of incarcerated individuals (N = 234) was investigated. A principal components analysis followed by Varimax rotation identified the familiar Perceptual Organization and Verbal Comprehension factors. Coefficients of congruence between the current factors and those of the WAIS-R standardization sample indicate a high degree of correspondence. Thus, empirical support was provided for interpretation of WAIS-R Performance and Verbal IQs in this population.

Estimated intelligence and long-term outcomes of opioid addicts.

This study estimated intellectual functioning based upon a demographic profile (DP) for Wechsler Adult Intelligence Scale-Revised (WAIS-R) Full Scale IQ in order to determine its relationship with variables representing initiation, continuation, relapse, and cessation of daily opioid use. The DP Estimated IQs were used to describe a large former opioid addict sample from the 12-year follow-up study of the Drug Abuse Reporting Program (DARP). Results were compared with those from previous studies using meta-analysis. In addition, a correlational analysis was performed. Average DP Estimated IQs for the DARP sample were comparable to mean IQs for both the WAIS-R standardization sample and previous studies. DP Estimated IQ was significantly related to length of addiction career; the higher the estimated IQ, the shorter the career. Other more complex relationships were found for variables used to represent intraindividual factors such as satisfaction with self or family, interpersonal factors such as family or peer influences, and other variables of interest.