A comparative study of general intelligence in Spanish and Moroccan samples

Normative and Equated Data of the Original and Basic Versions of the Montreal Cognitive Assessment among Community Dwelling Saudi Arabians

Introduction

Currently, there are standard and basic versions of the MoCA, the latter designed for those with lower educational achievements. Community-based normative data on these versions of the MoCA from Arabic populations are deficient, and there is little data demonstrating how both scales perform in comparison. We aim to obtain normative performances from both versions and equate the measures of both scales.

Methods

Community-based recruitment of healthy volunteers ≥ 18 years of age. Participants underwent testing with both versions. Demographic data was collected with regard to age, gender, years of education, diabetes, and hypertension. Regression analysis was performed to determine significance of variables, and the circle-arc equating method was used to equate the two scores from each scale.

Results

311 participants were included in the study. The mean (sd) age was 45.8 (15.96), females were 184 (59.16%), and the duration of education was 12.7 (5.67) years. The mean scores on the MoCA-A and MoCA-B were 21.47 (4.53) and 24.37 (4.71) (P < 0.0001), respectively. Multivariate regression showed significance of age and years of education in both versions (both variables with P < 0.0001). Correlation coefficient between the two scales was 0.77 (P < 0.0001). The largest equated difference between both MoCA versions was four points in those scoring from 10-20 on the MoCA-A.

Conclusion

We present normative data from a large Saudi Arabian community-based sample with two different MoCA tests, and an equating graph is presented to determine the corresponding expected performance between the two scales.

Spearman's hypothesis tested comparing Korean young adults with various other groups of young adults on the items of the Advanced Progressive Matrices

Spearman's hypothesis tested at the subtest level of an IQ battery states that differences between races on the subtests of an IQ battery are a function of the g loadings of these subtests, such that there are small differences between races on subtests with low g loadings and large differences between races on subtests with high g loadings. Jensen (1998) stated that Spearman's hypothesis is a law-like phenomenon. It has also been confirmed many times at the level of items of the Raven's Progressive Matrices. This study hypothesizes that with concern to Spearman's hypothesis, subtests and items function in fundamentally the same way, and tested whether Spearman's hypothesis is confirmed at the item level for White-East Asian comparisons. A group of Korean young adults (N=205) was compared with other groups of young adults from Canada, the US, Russia, Peru and South Africa (total N=4770) who took the Advanced Progressive Matrices. Spearman's hypothesis was strongly confirmed with a sample-size-weighted r with a value of 0.63. Computing the g loadings of the items of the Raven with either the Raven-g or the Wechsler-g led to the same conclusions. Tests of Spearman's hypothesis yielded less-strong outcomes when the 36-item Advanced Progressive Matrices were used than when the 60-item Standard Progressive Matrices were used. There is a substantial correlation between sample size and the outcome of Spearman's hypothesis. So, all four hypotheses were confirmed, showing that a part of the subtest-level nomological net replicates at the item level, strengthening the position that, with concern to Spearman's hypothesis, subtests and items function fundamentally the same. It is concluded that Spearman's hypothesis is still a law-like phenomenon. Detailed suggestions for follow-up research are made.

SPEARMAN'S HYPOTHESIS TESTED COMPARING SAUDI ARABIAN CHILDREN AND ADOLESCENTS WITH VARIOUS OTHER GROUPS OF CHILDREN AND ADOLESCENTS ON THE ITEMS OF THE STANDARD PROGRESSIVE MATRICES

Spearman's hypothesis tested at the level of items states that differences between ethnic groups on the items of an IQ test are a function of the g loadings of these items, such that there are small differences between ethnic groups on items with low g loadings and large differences between ethnic groups on items with high g loadings; this has been confirmed in a limited number of studies. In this paper, Spearman's hypothesis was tested, comparing a group of Saudi children and adolescents (N=3209) with other groups of children and adolescents from Denmark, Cyprus, Croatia, Bosnia, South Africa, Estonia, Ukraine, Ireland, Russia and Chile (total N=9333). The analyses were carried out on twelve comparisons between the Saudi Arabian children and the other children. Spearman's hypothesis was confirmed less strongly than in other large-scale studies with a mean weighted r value of 0.44. The relevance of these findings for the discussion on the causes of group differences is discussed.

Cultural differences in neuropsychological abilities required to perform intelligence tasks

Different studies have demonstrated that culture has a basic role in intelligence tests performance. Nevertheless, the specific neuropsychological abilities used by different cultures to perform an intelligence test have never been explored. In this study, we examine the differences between Spaniards and Moroccans in the neuropsychological abilities utilized to perform the Beta III as a non-verbal intelligence test. The results showed that the Spaniard group obtained a higher IQ than the Moroccan group in the Beta III. Moreover, the neuropsychological abilities that predicted scores for the Beta III were dependent on the country of origin and were different for each subtest. Besides showing the cultural effect on non-verbal intelligence test performance, our results suggest that a single test may measure different functions, depending on the subject's cultural background.