Mervyn Skuy’s research while affiliated with University of the Witwatersrand and other places

In previous studies significant differences in measured intelligence between African and non-African first year engineering students have been found. Intellectual ability was found to correlate with academic performance, and black studednts had higher dropout and failure rates and performed less well than did their non-African counterparts. Given the low magnitude (r = 0.3), albeit significant, of the correlation between intelligence and academic performance, the question arose of the role of non-intellective factors, relative to intelligence, in determining academic performance of engineering students at University. Accordingly, 93% (n=100) of the second year Chemical and Metallurgical Engineering class were assessed on two measures of intellectual ability, and on measures of self concept, motivation, study attitudes and strategies, anxiety, locus of control, and autonomy. Whereas the intelligence test scores of non-African students (n=36) were significantly higher than those of African students (n=64), this was not the case for any of the non-intellective measures, or for academic achievement. Moreover, although the intellectual measures did not yield significant correlations with academic achievement, certain of the non-intellective measures did, and were able to differentiate between high and low academic performers. This was particularly true for the African group, suggesting that non-intellective variables can contribute significantly to academic performance, particularly in mitigating the effects of lower IQ.

We test the hypothesis that the Raven's Advanced Progressive Matrices has the same construct validity in African university students as it does in non-African students by examining data from 306 highly select 17- to 23-year olds in the Faculties of Engineering and the Built Environment at the University of the Witwatersrand (177 Africans, 57 East Indians, 72 Whites; 54 women, 252 men). Analyses were made of the Matrices scores, an English Comprehension test, the Similarities subscale from the South African Wechsler Adult Intelligence Scale, end-of-year university grades, and high-school grade point average. Out of the 36 Matrices problems, the African students solved an average of 23; East Indian students, 26; and White students, 29 (p<.001), placing them at the 60th, 71st, and 86th percentiles, respectively, and yielding IQ equivalents of 103, 108, and 118 on the 1993 US norms. The same pattern of group differences was found on the Comprehension Test, the Similarities subscale, university course grades, and high-school grade-point average. The items on the Matrices ‘behaved’ in the same way for the African students as they did for the non-African students, thereby indicating the test's internal validity. Item analyses, including a confirmatory factor analysis, showed that the African/non-African difference was most pronounced on the general factor of intelligence. Concurrent validity was demonstrated by correlating the Matrices with the other measures, both individually and in composite. For the African group, the mean r=.28, p<.05, and for the non-African group, the mean r=.27, p<.05. Although the intercepts of the regression lines for the two groups were significantly different, their slopes were not. The results imply that scores on the Raven's Matrices are as valid for Africans as they are for non-Africans.

The hypothesis is tested that the Raven's Advanced Progressive Matrices (APM) has the same construct validity in African university students as it does in non-African university students. Analyses were made of scores from 294 highly select 17–23-year-olds in the Faculties of Engineering and the Built Environment at the University of the Witwatersrand (187 Africans, 40 East Indians, 67 Whites; 70 women, 224 men). Out of a total of 36 problems, the African students solved an average of 22, the East Indian students, 25, and the White students, 29 (P<.001), placing them at the 57th, 64th, and 86th percentiles, respectively, and yielding IQ equivalents of 103, 106, and 117 on the 1993 US norms. Four months earlier, they had completed the Standard Progressive Matrices. The two tests correlated .60 or higher for both the Africans and the non-Africans, and both tests predicted final end-of-year grades with mean r's=.30 (P's<.05). Items found difficult by one group were difficult for the others; items found easy by one group were easy for the others (mean r's=.90, P<.001). The African–East Indian–White differences were “Jensen Effects,” being most pronounced on the general factor of intelligence (measured in this instance by items with the highest item-total correlations). Indeed, the g loadings showed cross-cultural generality: For example, item-total correlations calculated on the East Indian students predicted the magnitude of the African–White differences. When each of the 36 g loadings and race effects were aggregated into nine four-item “subtests,” the magnitude of the Jensen Effect was Spearman's ρ=.52. There were no sex differences.

Widespread learning problems among South African children are associated with the apartheid era and show a need for effective reading programs. In selecting these programs, it is useful to differentiate between children with dyslexia and children whose reading is poor because teaching was inadequate. In this study, the Woodcock Tests of Reading Mastery-Revised and tests modelled on the Cognitive Assessment System were used to define a group of children with deficits in successive processing associated with dyslexia and a group of children with general reading delay. There were two girls and five boys in each group. For the children with successive processing deficit, the mean age was 9 yr., 8 mo. For the other group, mean age was 9 yr., 3 mo. Control groups were matched for age and sex and kind of reading difficulty. The first group received Das's PASS Reading Enhancement Program, and the second participated in a remedial program based on Whole Language principles. The treatment groups received 24 1-hr. long sessions. Gains in successive processing were shown for the first group, as measured by the tests modelled on Cognitive Assessment System subtests but not for the second group. Both groups showed gains in phonics and word identification, relative to their respective control groups, suggesting the respective intervention program was effective for each group.

Low test scores are routinely observed in sub-Saharan African populations. In this paper, we explore the topic further by examining Rushton and Skuy's [Intelligence 28 (2000) 251] hypothesis that a bimodal distribution exists in the African population with a high-scoring group virtually indistinguishable from Whites, and a low-scoring group performing significantly below both Whites and the higher-scoring African group. To test this hypothesis, we sought out a potentially higher-scoring African population than has previously been studied. We administered untimed Raven's Standard Progressive Matrices (SPM) to 342 17- to 23-year-olds in the Faculties of Engineering and the Built Environment at the University of the Witwatersrand in Johannesburg (198 Africans, 86 Whites, 58 Indians; 71 women, 271 men). Out of the 60 total problems, the African students solved an average of 50, the Indian students, 53, and the White students, 56 (P<.001). On the 1993 US norms, Africans were at the 41st percentile, Indians at the 55th, and Whites at the 75th, with IQ equivalents of 97, 102, and 110, respectively. The African–Indian–White differences were most pronounced on those items with the highest item-total correlations, indicating a difference in g, or the general factor of intelligence. Hence, they were “Jensen Effects.” Indeed, the g loadings showed a small degree of cross-cultural generality; for example, item-total correlations calculated on the Indian students predicted the magnitude of the White–African differences. When the 60 items were aggregated into 10 “subtests,” the magnitude of the Jensen Effect was similar to that from previous studies based on whole subtests (median ρ=.53). There were no sex differences. Nor did this study of African engineering students support the idea of a bimodal distribution.

Rushton and Skuy [Intelligence 28 (2000) 1.] found that White university psychology students in South Africa averaged between one and two standard deviations higher than African students on Raven's Standard Progressive Matrices. This new study was carried out to determine whether Feuerstein's Mediated Learning Experience would improve the scores of the African students. The sample comprised 70 African and 28 non-African first year psychology students. Subjects were given the Raven's on two occasions and, in-between, randomly constituted experimental groups were exposed to mediated learning experience. Both the African and non-African groups improved over the baseline on the Raven's compared to the control groups, with significantly greater improvement for the African group.

An Experimental Astronomy Curriculum or Thinking Journey was developed on the basis of a combination of Constructivism and Mediated Learning Experience (MLE). The Thinking Journey was designed to serve as a vehicle for promoting a process of conceptual change in a wide range of students. Its theoretical background, curriculum and an experiment to test its effectiveness with a class of low functioning high school girls are documented here. The study included an experimental (E) and control (C) group, each of which comprised 16 9th grade students. E focused on the concept of Earth within the framework of the Thinking Journey, while C was exposed to the conventional approach to the study of Earth within the Earth Studies curriculum. The results indicated the relative effectiveness of the Thinking Journey in promoting a process of positive change in the students' conceptualization of Earth, improving their knowledge of astronomy, enhancing their general scientific knowledge and developing their cognitive functioning and problem solving abilities. These findings are discussed in terms of the usefulness of utilizing a scientific subject as part of an educational intervention designed to enhance the cognitive abilities of low functioning students.

Mediated Learning Experience (MLE) is proposed here as an effective basis for bridging educational gaps and for promoting crosscultural co-existence and integration. A series of controlled studies in South Africa with pre-service teachers from a disadvantaged community, and with students of different cultural groups, developed and tested programmes based on MLE and on its vehicles, the Instrumental Enrichment (IE) thinking skills programme and the Learning Potential Assessment Device (LPAD). The unique nature of South Africa's sociopolitical situation, and the needs of particular population groups within this country, have served as the impetus for studying the effects of MLE, IE and the LPAD in conjunction with other constructs, approaches or programmes. These studies suggest the potential value of MLE-based intervention programmes in contributing to the transformation of the South African education system from its previous apartheid-based methods and goals of compliance, conformity and passive absorption of information, to an integrated and cognitively based system.

Variations in neuropsychological test performance as a function of ethnic/cultural group membership, socioeconomic and educational status are widely documented. In South Africa, issues of cultural difference, sociopolitical disadvantage, cognitive and educational limitations, are of particular relevance. Accordingly, this study investigated the performance on a neuropsychological test battery of urban African high school students. A group of 100 Soweto students in Grades 8–12, and a second group of 152 sixth grade Soweto students aged 13–15 years, scored significantly lower on most of the measures than their American counterparts, as reflected in published norms. Results also demonstrated a significant difference in test performance as a function of educational grade. The findings confirmed the need for using norms and approaches which are appropriate to a given population when interpreting and addressing neuropsychological test performance.

The new political dispensation in South Africa has replaced the content-oriented, rote-learning based curriculum of the previous regime with an Outcomes Based Education (OBE) approach. OBE is compatible with the developments in cognitive education in general, and with Feuersteine's Instrumental Enrichment (IE) thinking skills programme in particular. Accordingly, this study investigated the effectiveness of involving teachers in an IE programme in improving their ability to implement OBE in their schools. Eighteen teachers from four schools catering for historically disadvantaged black students participated in the programme over a period of eighteen months (58 school weeks). Teachers were trained in the application of the IE programme itself, and in the infusion of its cognitive principles and strategies in their subject content and goals. Findings suggested the usefulness of an IE-based programme in providing teachers with the appropriate attitudes and skills for implementing the Outcomes Based Education approach with students who have special educational needs.