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Raven's test performance of sub-Saharan Africans: Average performance, psychometric properties, and the Flynn Effect
Abstract
This paper presents a systematic review of published data on the performance of sub-Saharan Africans on Raven's Progressive Matrices. The specific goals were to estimate the average level of performance, to study the Flynn Effect in African samples, and to examine the psychometric meaning of Raven's test scores as measures of general intelligence. Convergent validity of the Raven's tests is found to be relatively poor, although reliability and predictive validity are comparable to western samples. Factor analyses indicate that the Raven's tests are relatively weak indicators of general intelligence among Africans, and often measure additional factors, besides general intelligence. The degree to which Raven's scores of Africans reflect levels of general intelligence is unknown. Average IQ of Africans is approximately 80 when compared to US norms. Raven's scores among African adults have shown secular increases over the years. It is concluded that the Flynn Effect has yet to take hold in sub-Saharan Africa.
... The term is often misunderstood because of incorrect beliefs that many people have about intelligence (Warne, 2020;Warne & Burton, 2020) and because of historical and cultural baggage surrounding the term "IQ." The first vital point to understand is that IQwhether a score for an individual or a mean for a group-is merely a measurement or number and is not the same as the underlying construct of intelligence (see also Haier, 2017;Hunt & Carlson, 2007;Warne, 2020;and Wicherts et al., 2010a, c; for this distinction). Consequently, I ask readers to not think of "IQ" and "intelligence" as always being synonymous. ...
... For example, most of the studies in sub-Saharan Africa that contributed data to Lynn and Becker's (2019b) national IQ dataset were nonverbal matrix reasoning tests (e.g., Raven's Progressive Matrices). There is strong evidence that in many sub-Saharan African samples, matrix tests do not function the same way as in Western samples (Becker et al., 2022;Dutton et al., 2018;Wicherts et al., 2010a). Thus, I am extremely skeptical of the validity of interpreting national IQs in many of these countries as reflecting the average intelligence of their citizens. ...
... In short, people who use Lynn and Becker's (2019b) dataset do not know how comprehensive the underlying data are or whether search procedures might systematically favor some research literature (e.g., articles published in English). This is a criticism that was been made of earlier versions of the national IQ dataset (Wicherts et al., 2010a, c), and it still applies to the most recent version (Lynn & Becker, 2019b). ...
Estimates of mean IQ scores for different nations have engendered controversy since their first publication in 2002. While some researchers have used these mean scores to identify relationships between the scores and other national-level variables (e.g., economic and health variables) or test theories, others have argued that the scores are without merit and that any study using them is inherently and irredeemably flawed. The purpose of this article is to evaluate the quality of estimates of mean national IQs, discuss the validity of different interpretations and uses of the scores, point out shortcomings of the dataset, and suggest solutions that can compensate for the deficiencies in the data underpinning the estimated mean national IQ scores. My hope is that the scientific community can chart a middle course and reject the false dichotomy of either accepting the scores without reservation or rejecting the entire dataset out of hand.
... These group comparisons have been repeatedly criticized on methodological grounds (e.g., Kamin, 2006;Neisser et al., 1996;Wicherts et al., 2010a, b). For example, some African samples with higher ability seem to have been excluded from inter-country comparisons without justification (see Wicherts et al., 2010a), not all samples are of a high quality (Lynn & Vanhanen, 2002, famously used average IQ at a school for the handicapped and brain-damaged in Spain as an estimate for average intelligence in Equatorial Guinea; see Kamin, 2006;Wicherts et al., 2010b), and some experiments might not have been quite neutral ("a certain awe and reverence which the native has for the white man ensured in every case at least a perfunctorily co-operative attitude"; Nissen et al., 1935). Critically, however, the basic point stands: "Blacks" score consistently lower than "Whites." ...
... Throughout the world, most ethnic groups do score consistently lower than Western subjects on visuospatial tests such as Raven's matrices (for a large-scale comparison, see Brouwers et al., 2009). This is a robust result and not a matter of debate (see Wicherts et al., 2010a). The actual issue is not about the existence of this score difference, but about its interpretation (e.g., Steele, 1997). ...
... Moreover, the psychometric properties of nonverbal tests may be significantly worse in populations that are culturally very distant from Western samples. A detailed review of the use of Raven's matrices in African samples (Wicherts et al., 2010a) showed that the test had a lower g-loading and lower convergent validity than in Western samples, that it demonstrated violations of unidimensionality, and that there was overall little support for its measurement invariance across cultures. ...
Visuo-spatial reasoning tests, such as Raven’s matrices, Cattell’s culture-fair test, or various subtests of the Wechsler scales, are frequently used to estimate intelligence scores in the context of inter-racial comparisons. This has led to several high-profile works claiming that certain ethnic groups have lower intelligence than others, presumably due to genetic inferiority. This logic is predicated on the assumption that such visuo-spatial tests, because they are non-verbal, must be culture-fair: that their solution process does not significantly draw on factors that vary from one culture to the next. This assumption of culture-fairness is dubious at best and has been questioned by many authors. In this article, I review the substantial body of psychological and ethnographic literature which has demonstrated that the perception, manipulation and conceptualization of visuo-spatial information differs significantly across cultures, in a way that is relevant to intelligence tests. I then outline a model of how these inter-cultural differences can affect seven major steps of the solution process for Raven’s matrices, with a brief discussion of other visuo-spatial reasoning tests. Overall, a number of cultural assumptions appear to be deeply ingrained in all visuo-spatial reasoning tests, to the extent that it disqualifies the view of such tests as intrinsically culture-fair and makes it impossible to draw clear-cut conclusions from average score differences between ethnic groups.
... All testing took place in an examination room at the hospital. Given the challenges of assessing cognitive development in children in low-income settings, including in sub-Saharan Africa (Wicherts, Dolan, Carlson, & van der Maas, 2010), careful consideration was taken to select measures that had been applied successfully in previous studies with children from sub-Saharan Africa (e.g., Bakare, Ubochi, Okoroikpa, Aguocha, & Ebigbo, 2009, Wicherts et al., 2010. Measures were selected that included only minimal language demand from participants. ...
... All testing took place in an examination room at the hospital. Given the challenges of assessing cognitive development in children in low-income settings, including in sub-Saharan Africa (Wicherts, Dolan, Carlson, & van der Maas, 2010), careful consideration was taken to select measures that had been applied successfully in previous studies with children from sub-Saharan Africa (e.g., Bakare, Ubochi, Okoroikpa, Aguocha, & Ebigbo, 2009, Wicherts et al., 2010. Measures were selected that included only minimal language demand from participants. ...
... First, children were administered the Raven's Standard Progressive Matrices (Raven, 1998), a nonverbal test measuring abstract reasoning and regarded as an estimate of fluid intelligence in children ages 6-16. The Raven's has been previously used in research with children in sub-Saharan Africa (Wicherts et al., 2010). Items consist of visual geometric designs with a missing piece. ...
Children with sickle cell anemia (SCA) have elevated cerebral blood velocity relative to healthy peers. The primary aim of this study was to evaluate the association between cerebral blood velocity, measured by transcranial Doppler (TCD) ultrasound, age, and gender with cognitive function in children with SCA in Nigeria. Eighty-three children (Mage = 9.10, SD = 1.90 years; 55% female) with SCA in Nigeria completed cognitive assessments and a TCD ultrasound. The association between TCD velocity and measures of perceptual reasoning (Raven’s Progressive Matrices), working memory (WISC-IV Digit Span), and executive planning (Tower of London, TOL) were assessed. Results showed that elevated TCD velocity significantly predicted lower scores on TOL Time Violations and Total Problem-Solving Time when controlling for BMI, hemoglobin level, and parent education, suggesting that TCD velocity is related to the efficiency of executive function. Further, age was negatively related to children’s performance on the Ravens Matrices and TOL Total Correct, and boys showed greater deficits on the TOL Total Correct relative to girls. Moderation analyses for gender showed that there was a conditional negative association between TCD velocity and Digit Span for boys, but not for girls. Findings suggest that children with SCA in Nigeria with elevated TCD velocity are at risk for deficits in efficiency of executive planning, and boys with elevated TCD velocity are particularly at increased risk for deficits in auditory working memory. Implications of this study are important for interventions to reduce cerebral blood velocity and the use of TCD in this population.
... (We will explore this in more detail below). Wicherts et al. (2010) observe that much of Sub-Saharan Africa would thus be yet to experience a Flynn Effect. Moreover, they argue that, in a Sub-Saharan African context, it is highly questionable whether Raven's is culture fair and the conditions under which the test-takers take the tests may be sub-optimal in comparison to those of Western test-takers. ...
... However, it is clearly not justifiable with regard to South Sudan, which is south of the Sahara. Since Wicherts et al. (2010) published their analysis, Raven's has been administered to a number of South Sudanese samples. In this study, we will present and analyze these administrations. ...
... Moreover, even where the score is around 15 or 20, it is still probable that approximately half of the sample had no understanding of what they were supposed to be doing. These kinds of low scores would be consistent with the observation of Wicherts et al. (2010) that the very nature of these tests may be inherently baffling to many Sub-Saharan Africans, meaning that they are simply not suitable. It is possible that they are unfamiliar with colour-printed material, inexperienced with using a pencil, unfamiliar with geometric shapes, unfamiliar with multiple choice tests, generally unfamiliar with taking formal tests of any kind, and, certainly, unfamiliar with IQ tests. ...
It has been argued that Raven's tests are problematic in the context of Sub-Saharan Africa. No discussion of Raven's in South Sudan, one of the least developed countries in Africa, has been presented. We present all known administrations of Raven's to South Sudanese samples. We find that Raven's in South Sudan is problematic. The scores are so low that they may imply that the subjects had little understanding of the test and simply guessed the answers. It is argued that the undeveloped nature of South Sudan means that a test based around shapes and analytic thinking is unsuitable. It is likely to heavily underestimate their average intelligence.
... Others disagree. Wicherts, Dolan, Carlson, and van der Maas (2010) carried out a systematic literature review of selected published data on performances on the Standard Progressive Matrices (SPM) and the Coloured Progressive Matrices (CPM) in Sub-Saharan African countries. Initially they calculated a score only using papers that complied with certain criteria (i.e. ...
... no time limit for the test, the test rules were followed, sample size representable of the population) critiquing the methodological approach of Lynn and Vanhanen's (2002) who did not justify study selection. Wicherts et al. (2010) found utilising the selective methodology that IQ scores in Africa (based on SPM and CPM) were somewhere between 78 (UK standards) and 80 (US standards), 11 IQ points higher than Lynn and Vanhanen (2002) had reported. An investigation by Wicherts et al. (2010) into the reliability of the Raven's test based on African samples (countries included Nigeria, Ghana, South Africa, Congo, Kenya, Uganda and Zambia) suggested a high level of concordance (.80 Cronbach's alpha) in line with findings from western studies. ...
... Wicherts et al. (2010) found utilising the selective methodology that IQ scores in Africa (based on SPM and CPM) were somewhere between 78 (UK standards) and 80 (US standards), 11 IQ points higher than Lynn and Vanhanen (2002) had reported. An investigation by Wicherts et al. (2010) into the reliability of the Raven's test based on African samples (countries included Nigeria, Ghana, South Africa, Congo, Kenya, Uganda and Zambia) suggested a high level of concordance (.80 Cronbach's alpha) in line with findings from western studies. However, they report that the retest reliability conducted after 6 months was quite low (.59) and concurred with the literature in their study. ...
The research set out in this paper attempts to identify whether one of three conventional IQ tests is more capable of identifying intellectual potential amongst poor children in Dar es Salaam. To this end 1857 children from 17 government schools in poor districts of Dar es Salaam were asked to complete a questionnaire and undertake a range of tests. The study included teacher, peer and self-nomination. It has been noted that static testing may not fully elicit the abilities of African children. It has been suggested that dynamic testing might provide a more fair and equitable means of assessment. Therefore 101 students took part in a control and intervention group in order to investigate. The findings show a significant correlation between IQ test scores and other test outcomes. Those with larger families and older children perform less well on IQ tests. Peer ability and self-confidence positively influence test scores. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
... An additional problem arises in the translation from SPM/CPM raw scores to IQs in the extreme score ranges, where values in the norm tables show large leaps for particular age groups. 4 (Wicherts, Dolan, Carlson, & van der Maas, 2009) To refresh my reader's memory, Lynn and Vanhanen (2002) and Kanazawa (2006Kanazawa ( , 2007 have used IQ data of Ethiopian immigrants that came from Israel as the average IQ of Ethiopia. Most of these immigrants had rudimentary literacy and experienced an abrupt transition from rural Ethiopia to Israel, with all the accompanying effects that it entails such as trauma, dislocation, and cultural shock. ...
... Since 1950, we have become more ingenious in going beyond previously learned rules to solve problems on the spot (Flynn, 2006). Wicherts et al. (2009) outlined the problem of using Raven's Progressive Matrices to test African samples. They questioned its so-called cultural fairness and recommended -caution in the use of these tests with Africans for selection purposes in education and the global market.‖ ...
... Besides, Lynn and co-workers use convenience samples (Wicherts et al., 2009(Wicherts et al., , 2010a(Wicherts et al., , 2010b. Use of samples of convenience violates fundamental principles of research methodology and elementary statistical inferences to draw conclusions about populations, tests of significance when there is no theoretical basis to do so, and the confounding of association with causation. ...
... The observation that many children in developing countries did not complete primary school and those who completed, did not do as well as children in developed countries, has kindled researchers' interest in the relationship between nutritional status, health and educational achievement of school aged children in developing countries [22]. ...
... This poor performance led the noble Laureate James Watson to express gloom about the future of Africa, in the light of the finding that sub-Saharan Africans have lower average test scores than the people in other parts [22], though this seemingly poorer performance of Africans on test scores has been attributed to culturally unfair test instruments [18]. ...
The nutritional status of school-aged children impacts their health, cognition, and their educational achievement while poor health and malnutrition impair both the growth and cognitive development of primary school children. This study was carried out to assess the nutritional status and school performance of primary school children in Ogun state, Nigeria. A descriptive cross-sectional survey was conducted among 1200 pupils age 6-12 years old selected from 12 public Primary schools using multi-stage sampling techniques. Interviewer administered questionnaires were used to collect information on the socio-demographic variables of the subjects and also social economic variables of subject parents or guardians. Information on school performance was collected from the Ogun State Unified Examination record record from State Universal Basic Education Board (SUBEB). A 24 hour dietary recall method was used to collect information on the specific food intakes and usual portion sizes. Anthropometric measurements were measured using an electronic food weighing scale and height using a stadiometer. Data collected were subjected to descriptive, t-test and Chi- square statistics. Data on food intake were converted to nutrient intake using Total Diet Assessment software. Body Mass Index for age (BMI-for-Age) was calculated from anthropometric data generated using WHO Anthro software. Results shows that the mean and standard deviation age of the respondents were 11.04 ± 1.082 years while the minimum and maximum age was 8 years and 12 years old respectively. The mean weight range of the respondents was, 19.00kg to 70.00kg respectively. The mean height range was, 1.18m to 1.63m. The mean mathematics, English Language, social studied scores was 58.64 ± 13.740, 61.14 ± 14.086, 64.88 ±14.386 while minimum and maximum score were 20% and 99%, 19% and 99%, 18% and 97% respectively. Less than (47.1%) of the respondents have normal nutritional status while 45.80% were underweight, females were more underweight than male while male were overweight and obese than the female. School performance of the Respondents, 70.3% of the respondents had average score in mathematics, 22.3 % performed excellently and 7.4% had poor performance. Over half of the respondents, 69.3% had average score in English language while 26.2% were excellent and 4.6% were poor. 57.8% had average performance, 38.2 % had excellent and 4.0% had poor performances in social studies. Majority of the respondents had inadequate energy intake (83.8%), 2.0% had excess energy intake while 14.3% are adequate energy intake, more than half of respondents (54.3%) Carbohydrate intakes were inadequate while 39.8% had adequate carbohydrate intake and 5.9% had excess intake of carbohydrate. For Protein, 80.0% had inadequate protein intake, 17.3% had adequate protein intake while 2.8 had excess intake. 97.5% of the respondent had inadequate Fat intake while 1.8% had adequate intake and 0.8 had excess intake. 72.7% of the respondents had inadequate intake of Vitamin A, 17.0% had adequate intake, 10.3% had excess intake, for Vitamin C, 99.0% had inadequate intake, 0.8%, had adequate intake, 0.3% had excess, 46.0% had inadequate intake of Folate, 21.5%, had adequate intake, 32.5% had excess intake, for Calcium, 98.8% of the respondents had inadequate intake, 0.8%, had adequate intake, 0.4% had excess intake, 89.0% of the respondents had inadequate of Zinc, 10.5 had adequate intake and 0.5% had excess intake, for Iron 51.0% of the respondents had inadequate intake, 34.3% had adequate intake and 14.8% had excess intake. Significant relationship existed between the Height-for-Age, BMI-for-Age and school performance of the respondents, as height of the pupils increases there is an increase in their school performance and their body mass index have a positive effect on their school performance which were significant (p ≤ 0.05) except mathematics score.
... Singapore, Israel, and Sudan have been singled out for having national IQs that are distinctly higher than the ranges given for their respective regions. Wicherts et al. (2010) found that the correlation between scores on Raven's IQ tests and g, a general factor of intelligence extracted from the results of cognitive-ability subtests, is .55 in samples from sub-Saharan Africa. This correlation is not as strong as the .80+ ...
... Whether there is strict measurement invariance between African and Western IQ scores, as maintained by Taylor (2008), is debatable. Wicherts et al. (2010) were skeptical. Jones (2012) has said that if the IQ scores across countries and world regions are "biased", then "they appear to be biased in favor of productivity growth." ...
This paper offers a review of some of the empirical literature on economic growth and discusses its recent evolution in light of developments in intelligence research and genomics. The paper also undertakes the first regression analysis of economic growth to use the most up-to-date version (VI.3.2) of David Becker's data set of international IQ scores. The analysis concerns the growth of 94 countries from 1995-2016. The new regression analysis replicates the results of Jones and Schneider (2006) in finding IQ to have a robust impact on economic growth. Political and economic institutions are represented in the regressions via a country's "degree of capitalism" (aka "economic freedom"), which is found to have an impact that is positive and statistically significant. A change from communism to a market economy does much to increase growth, but the paper finds diminishing returns to free markets. Countries whose people are mostly of sub-Saharan African descent have low average IQ scores, but the paper finds that other factors also have lessened economic growth not only in Africa, but in Haiti and Jamaica as well. Rushton and Jensen (2005, 2010) put forth the hypothesis that average IQ differences across ethnic groups are 50% due to genetic differences, and 50% due to differences in natural and social environments. Applied to international IQ scores, the paper finds the hypothesis to be very reasonable.
... However, these approaches have been brought into question [11]. The critics noted, in particular, that the method of correlated vectors "does not address the issue of measurement invariance" [12]. It is worth noting that the method of correlated vectors was criticized when applied to testing Spearman's hypothesis [13,14], and in studies aiming to show the heritability of group differences in intelligence [15]. ...
... To date, there have been few studies in which DIF analysis was applied to interethnic comparisons using Raven's Matrices. Wicherts et al. in 2010 [12] noted that they were aware of only one such study by Taylor (2008), in which item response theory (IRT) was used in the analysis [20]. We also managed to find another pre-2010 study by Vanderpool and Catano (2008), which involved a DIF analysis of Raven's Matrices (and other tests) using logistic regression [21]. ...
National IQ estimates are based on psychometric measurements carried out in a variety of cultural contexts and are often obtained from Raven’s Progressive Matrices tests. In a series of studies, J. Philippe Rushton et al. have argued that these tests are not biased with respect to ethnicity or race. Critics claimed their methods were inappropriate and suggested differential item functioning (DIF) analysis as a more suitable alternative. In the present study, we conduct a DIF analysis on Raven’s Standard Progressive Matrices Plus (SPM+) tests administered to convenience samples of Yakuts and ethnic Russians. The Yakuts scored lower than the Russians by 4.8 IQ points, a difference that can be attributed to the selectiveness of the Russian sample. Data from the Yakut (n = 518) and Russian (n = 956) samples were analyzed for DIF using logistic regression. Although items B9, B10, B11, B12, and C11 were identified as having uniform DIF, all of these DIF effects can be regarded as negligible (R2 <0.13). This is consistent with Rushton et al.’s arguments that the Raven’s Progressive Matrices tests are ethnically unbiased.
... Although not part of our preregistration, we expanded our search procedures by examining the reference lists of every article that contained usable data for our study and of five articles about intelligence levels in developing nations (Lynn, 2010;Rindermann, 2013;Wicherts, Dolan, Carlson, & van der Maas, 2010a, 2010bWicherts, Dolan, & van der Maas, 2010) and Lynn's (2015) compilation of worldwide IQ test results. We also found that searching for specific intelligence test names, coupled with the terms "cognitive" or "intelligence" and a country name (e.g., Wechsler intelligence Ghana) in Google Scholar was productive. ...
... The existence of g in all of these cultures shows that-contrary to the opinions of cultural relativists (e.g., Berry, 1986)-such comparisons may be possible, though the practical hurdles to creating tests for dissimilar cultures show that establishing measurement invariance across groups may be very difficult to overcome (Church & Katigbak, 1987). Even popular tests that are supposedly usable in many cultures-such as the drawa-person test or the Raven's matrices-sometimes function poorly when administered to non-Western examinees (Dutton et al., 2018;Kathuria & Serpell, 1998;Wicherts et al., 2010a), and considerable work may be necessary to measure the cultural manifestations and indicators of general cognitive ability in some groups. Investigators who wish to make cross-cultural comparisons must demonstrate that (a) their tests are appropriate for examinees' cultures, (b) examinees understand the instructions and how to respond to test items, and (c) the tests demonstrate measurement invariance across groups. ...
Spearman’s g is the name for the shared variance across a set of intercorrelating cognitive tasks. For some—but not all—theorists, g is defined as general intelligence. While g is robustly observed in Western populations, it is questionable whether g is manifested in cognitive data from other cultural groups. To test whether g is a cross-cultural phenomenon, we searched for correlation matrices or data files containing cognitive variables collected from individuals in non-Western, nonindustrialized nations. We subjected these data to exploratory factor analysis (EFA) using promax rotation and 2 modern methods of selecting the number of factors. Samples that produced more than 1 factor were then subjected to a second-order EFA using the same procedures and a Schmid-Leiman solution. Across 97 samples from 31 countries totaling 52,340 individuals, we found that a single factor emerged unambiguously from 71 samples (73.2%) and that 23 of the remaining 26 samples (88.5%) produced a single second-order factor. The first factor in the initial EFA explained an average of 45.9% of observed variable variance (SD = 12.9%), which is similar to what is seen in Western samples. One sample that produced multiple second-order factors only did so with 1 method of selecting the number of factors in the initial EFA; the alternate method of selecting the number of factors produced a single higher-order factor. Factor extraction in a higher-order EFA was not possible in 2 samples. These results show that g appears in many cultures and is likely a universal phenomenon in humans.
... Later, scientists have found such claims to have been based on flawed science. Wicherts et al. [9] examined, perhaps nearly all the then available IQ studies conducted on Africans from 1988 to 2006, and found about 2500 papers. The data were subjected to scientific methods of sample selection criteria and then analysed. ...
... They found that the average IQ had no indication to general intelligence among Africans. Furthermore, environmental factors that are known to improve IQ such as good health, better nutrition, opportunities to education etc. lack among most of Africa's young population [9]. ...
... The reliability and criterion validity of Raven's Matrices have been found to be good in Africa (Wicherts et al. 2010;Costenbader & Ngari 2001). Our finding that Raven's score and the other three outcome measures were associated with schooling also supported their criterion validity. ...
... Our finding that Raven's score and the other three outcome measures were associated with schooling also supported their criterion validity. However, there is a concern that, in Africa, it may not measure 'general intelligence', or 'g', as intended (Wicherts et al. 2010). More detailed psychometric assessment and analysis will be needed to clarify its properties. ...
Stunting is a measure of chronic undernutrition, and it affects approximately 160 million children worldwide. Cognitive development of stunted children is compromised, but evidence about the association between height gain in late childhood and adolescent cognitive capacity is scarce. We aimed to determine the association between height gains at different ages, including late childhood, and cognitive capacity at 15-years-of-age. We conducted a prospective cohort study in a rural African setting in Southern Malawi. The study cohort was enrolled between June 1995 and August 1996. It originally comprised mothers of 813 fetuses, and the number of children born live was 767. These children were followed up until the age of 15 years. The anthropometrics were measured at one and 24-months-of-age and 15-years-of-age, and cognitive capacity of participants was assessed at 15-years-of-age with Raven's Coloured Matrices score, mathematic test score, median reaction time (RT) (milliseconds) and RT lapses. The associations between growth and the outcome measures were assessed with linear regression. Raven's Coloured Matrices score was predicted by height gain between 24 months and 15-years-of-age (coefficient 0.85, P = 0.03) and (coefficient 0.69, P = 0.06), but not by earlier growth, when possible confounders were included in the model. The association weakened when school education was further added in the model (coefficient = 0.69, P = 0,060). In conclusion, in rural Malawi, better growth in late childhood is likely to lead to better cognitive capacity in adolescence, partly through more school education. In light of these results, growth promotion should not only be limited to early childhood.
... However, some authors have questioned the validity (both internal and external) of Lynn and Vanhanen's results, particularly pointing to the unrepresentativeness of some of their samples and the meaningfuhiess of applying generally US/UK-oriented paper-andpencil tests to people growing up in very different cultures (Bamett & Williams, 2004, 2005Hunt & Carlson, 2007). Wicherts and colleagues Wicherts, Dolan, Carlson & van der Maas, 2010a) also reviewed evidence of differences in national IQ. Disagreeing with Lynn and Vanhanen's claim that the IQ of sub-Saharan Afiican nations averaged below seventy, their systematic review suggested a figure of approximately eighty IQ points, the discrepancy between the two due mainly to different choices regarding sample inclusion. ...
... 3 Although an earlier version of Lynn's national IQ-database (see Lynn & Vanhanen, 2012) has received some justified criticisms (e.g. Moreale & Levendis, 2014;Wicherts et al., 2010), it bears mentioning that a recent assessment by Warne (2023) found that its latest iteration (see Lynn & Becker, 2019) possesses 'a great deal of validity evidence in favour of using it' notwithstanding certain persisting shortcomings and that its main findings are consistent with those of Rindermann (2018), who draws on tests such as PISA (Programme for International Student Assessment) and TIMSS (Trends in International mathematics and Science Study) to gauge what he terms 'national cognitive ability levels'. ...
... Therefore, it must be concluded that minor violations of measurement invariance on the PISA exams, and likely all scholastic tests, do not have a practically significant impact. Some researchers have argued that the samples of Africans who took the Raven's test collected by Lynn have low levels of convergent validity and are taken from unrepresentative samples (Wicherts et al., 2010). The low scores of Africans (70) on these tests cannot be blamed on selective sampling or reporting, as the average African IQ converges to an average of roughly 70 regardless of the source (Warne, 2022), including sources that rely solely on results from scholastic assessments. ...
Using 47 indicators of socioeconomic development and various sources of performance on cognitive tests, we constructed the SDI (socioeconomic development index) and a set of national IQs for 197 nations, the latter using no geographic imputations. Combining the various datasets reduced the estimated standard error of national IQs from 5.41 to 2.58, and a strong correlation between socioeconomic development and national IQs was observed (r = .88). Based on the prior that Flynn Effect gains do not pass measurement invariance, IQ scores should exhibit some non-negligible bias between countries. Empirical assessments of measurement invariance across nations finds that measurement invariance violations are uncommon and typically found when verbal tests are given. In most countries, national IQs show high levels of reliability and validity, and we encourage their use in the literature.
... Zambia mostly relies on a handful of diagnostic instruments that are developed in North American and European countries, then imported to Zambia. [3][4][5][6][7] Zambia shares the issue of over-reliance on imported instruments and the challenge of producing original tests with many other developing countries worldwide. Importantly, the adoption of tests developed and standardized in a distinct cultural and socioeconomic context carries the risk of poor cross-cultural validity, misrepresenting the cognitive abilities of children. ...
Objective:
The paucity of valid diagnostic tools is one of the challenges preventing the effective implementation of child cognitive health testing in Sub-Saharan developing countries. WAVES addresses the need for new psychometric tests to evaluate visuospatial construction ability in a school-aged population. WAVES involves the standardized administration of a copy design task that is sequentially repeated by four distinct reproduction modalities: copy design with open eyes (CDO), immediate reproduction from memory with open eyes (IRMO), immediate reproduction from memory with closed eyes (IRMC), and delayed reproduction from memory with closed eyes (DRMC).
Design:
WAVES reliability and validity were assessed in a field trial using Classical Test Theory or Item Response Theory (IRT) methods. A total of 445 children, aged 5 to 17 years old, were recruited at multiple Zambian clinical sites and schools.
Results:
WAVES provides a visuographomotor construction processing (VGCP) index and three subscale inaccuracy of reproduction scores: perseveration, decreased spacing, and changing direction difficulty (CDD). WAVES scores depended on age and showed an age-related increase of reproduction accuracy. Altered visuospatial construction, as indicated by higher scores, was associated with poor health status (i.e., chronic neurologic or medical disease or prolonged exposure to psychosocial stress and deprivation). Reliability estimates, expressed as an intraclass correlation coefficient (ICC; 95% confidence interval [CI]), at test-retest (n=86) were: VGCP Index: 0.94 (0.91, 0.96); perseveration: 0.76 (0.62, 0.84); decreased spacing: 0.86 (0.79, 0.91); and CDD: 0.93 (0.89, 0.95).
Conclusion:
WAVES has potential for clinical utility in evaluating the effect of different health conditions on visuospatial construction ability. Study results warrant further research to validate its use in healthcare and clinical research settings.
... But it is highly unlikely that it is even conceptually possible to construct a meaningful, comparable measure of cognitive ability which measures the same underlying construct from diverse populations. Psychometric tests are culturallyspecific, affected by education, by motivation, as well as a wide range of other environmental factors, and improve with coaching and on re-testing (Anum, 2014;Dramé & Ferguson, 2019;Duckworth, Quinn, Lynam, Loeber, & Stouthamer-Loeber, 2011;Kulik, Bangert-Drowns, & Kulik, 1984;Needleman & Gatsonis, 1990;Wicherts, Dolan, Carlson, & van der Maas, 2010b). Many of the studies included in the dataset provide clear evidence that the cognitive tests used are unsuitable for comparative work, and some include very clear statements that their samples should not be used for comparative purposes. ...
In 2002, Lynn and Vanhanen produced a dataset which claimed to provide average ‘national IQs’ for nation-states worldwide. Despite extensive critique, this dataset, and subsequent updated versions, have been used in a large number of empirical publications. Here I evaluate the latest version, produced in 2019 by Lynn and Becker, and show that this dataset is not fit for purpose. The primary data sources are inadequate for estimating ‘national IQs’. The majority of data included originates from samples which are wholly unrepresentative of their national populations. Many are convenience samples with small sample sizes, often including only children and often including individuals chosen because they had particular characteristics (i.e., samples which were deliberately chosen to be unrepresentative). Data were collected using a range of different cognitive tests and from such diverse populations that it is impossible to generate comparable measure of cognitive ability. There is also evidence that further bias may have been introduced during manipulations of primary data into ‘IQ’ scores. The extent of these biases differs by world region, meaning that the dataset is not only inaccurate but systematically biased. This ‘national IQ’ dataset therefore does not provide comparable, accurate and unbiased measures of cognitive ability worldwide, and should not be used be draw inferences about global variation in intelligence.
... Multitrait-multimethod matrix could be applied to assess convergent and discriminant validity, 18 and the use of tests originally developed or cross-culturally validated in Zambia should be prioritized. 8 The evaluation of Knowledge Processing in relation to intelligence, as measured by the Raven's Progressive Matrices 19 or the Panga Munthu test, is of particular interest. Studies have drawn attention to the importance attached to social intelligence in African cultures, such as the ability to deal with socially complex situations, which goes well beyond the traditional concept of intelligence as cognitive processing. ...
Objective:
The assessment of a child's cognitive health in developing countries poses significant challenges, including the paucity of valid diagnostic tools. We report the development and initial psychometric evaluation of a new eight-item cognitive ability assessment tool (CAAT-8) for use in an African Sub-Saharan school-aged population.
Design:
CAAT-8 reliability and validity were assessed in a field trial. Participants (446 children aged 5-17 years) were recruited at multiple clinical sites and schools. Methods and techniques based on Item Response Theory and Structural Equation Modeling were applied for item analysis and selection, reliability, and validity assessments.
Results:
CAAT-8 includes eight cognitive tasks and provides a reliable measure of the factor of Knowledge Processing. Knowledge Processing consistently increased over age (simple regression model, R2=0.44). A poorer health status (e.g., due to a neurological or medical condition or chronic exposure to psychosocial stress and deprivation) was associated with lower Knowledge Processing.
Conclusion:
CAAT-8 is a viable methodology for cognitive health assessment in a pediatric school-aged population. The results from this study warrant further research to validate its use in healthcare and clinical research settings.
... Participants were examined using the Wechsler Intelligence Scale for Children ® -Fourth Fluid intelligence was assessed using the Raven's Standard Progressive Matrices (RSPM), 33 a widely used intelligence test for typically developing (TD) children as well as for children with neurodevelopmental conditions. RSPM has previously been used in research with 8 children in Nigeria 30 and sub-Saharan Africa, 37 including those with SCA. 34 The trials are arranged in progressively increases of difficulty. ...
Background
Developmental difficulties in many cognitive domains are common in children with sickle cell anaemia (SCA). Children with stroke are most affected but delayed or atypical cognitive function has been reported in children with SCA and silent infarcts (SCI), vasculopathy, and normal brain MRI. However, very few studies of cognition have been conducted in Africa, a continent with 75% of the SCA burden. We therefore investigated cognitive profiles in Tanzanian children with SCA and examined the impact of age, SCI, vasculopathy, and haemoglobin concentration (Hb).
Methods
Children aged 6–16 years with and without SCA were eligible for this cross-sectional study. Cognitive assessment was performed using Raven’s Matrices, assessing fluid, non-verbal intelligence and subtests from the Wechsler Intelligence Scales for Children (WISC-IV), assessing processing speed (PS), perceptual reasoning (PR), and working memory (WM) as these tests are less culture-bound. Magnetic resonance imaging (MRI) and angiography (MRA) were also completed to assess the presence of SCI and vasculopathy. Hb was collected in both SCA children and their non-SCA siblings.
Results
Seventy-three children with SCA and 71 healthy siblings (Meanages 11.9, SD = 2.8 and 11.1, SD = 2.9 years respectively) were recruited. Compared with healthy siblings, children with SCA had lower PS (Meandiff 7.35 points; p = .002). Older children had higher performance scores on all tests in relation to their ages. Lowest cognitive scores were observed on the PS subtest, where patients with SCI (SCI+) had lowest mean values as compared to children with no SCI (SCI-) and healthy siblings (i.e., SCI+ < SCI- < healthy siblings, p = .028). On post-hoc analysis the difference was between SCI+ and healthy siblings SCI+ < non-SCA siblings (p = .015); there was no difference between SCI+ and SCI- patient groups. PS was significantly lower in SCA patients with no vasculopathy as compared to healthy siblings. The mean difference from healthy siblings was -8.352 and -0.752 points for VASC- and VASC + respectively (p = .004). There was a significant positive effect of Hb on PSI (p = .001) in both patients and controls and a trend level significant positive effect of Hb on PR (p = .050) and WM (p = .051).
Conclusion
In this Tanzanian study, cognitive performance was reduced in children with SCA with or without SCI on MRI or vasculopathy. Cognitive performance improved with increasing age. Lower Hb was associated with lower cognitive performance in both patients with SCA and their non-SCA siblings. SCI and vasculopathy do not appear to have an impact on cognitive function.
... 18 19 The reliability and criterion validity have been found good in Africa. 20 21 The test comprises 36 items; each correct answer provides a score of 1 and each incorrect or no answer is counted as 0. Two research assistants administered the Raven's test at the study clinic. ...
Objective
To assess whether intermittent preventive treatment of pregnant women (IPTp) with sulfadoxine-pyrimethamine (SP) and azithromycin (AZI) in a malaria-endemic area leads to sustained gains in linear growth and development in their offspring.
Design
Follow-up study of a randomised trial.
Setting
Mangochi District in rural southern Malawi.
Participants
1320 pregnant women and their offspring.
Interventions
IPTp monthly with SP and twice with AZI (AZI-SP group), monthly with SP but no AZI (monthly SP), or twice with SP (control). No intervention was given to children.
Main outcome measures
Cognitive performance using Raven’s Coloured Progressive Matrices (CPM) at 13 years of age; mean height and height-for-age Z-score (HAZ), cumulative incidence and prevalence of stunting (HAZ <−2); weight, body mass index, mid-upper-arm circumference and head circumference.
Results
At approximately 13 years of age, the mean CPM score was 14.3 (SD 3.8, range 6–29, maximum 36), with no differences between groups. Children in the AZI-SP group were on average 0.4 cm (95% CI −0.9 to 1.7, p=0.6) taller than those in the control group. For cumulative incidence of stunting, the HR in the AZI-SP group was 0.72 (95% CI 0.61 to 0.84, p<0.001) compared with the control and 0.76 (95% CI 0.65 to 0.90, p<0.001) compared with the monthly SP groups. There was no intergroup difference in stunting prevalence or anthropometric measurements.
Conclusions
In rural Malawi, maternal intensified infection control during pregnancy reduces offspring’s cumulative incidence of ever being stunted by 13 years of age. In this study, there was no evidence of a positive impact on cognitive performance.
Trial registration number
NCT00131235 .
... There has been discussion in the literature about the validity of Raven's Progressive Matrices as a measure of innate intelligence for sub-Saharan Africa especially given the confounding that has been observed between such measures and the level of development (Wicherts et al. 2010;Raven 2000;Raven and Court 1998). A systematic review of published data on Raven's tests in sub-Saharan African populations found that reliability is generally high (above 0.80) and that predictive validity was observed in several studies at levels comparable to western samples, but that convergent validity -the degree to which the scores correlate with other assessments of cognitive ability -is considerably lower by comparison to Western samples. ...
This paper presents results from a three-arm randomized controlled trial in Zambia with a sample of nearly 1200 adolescent girls enrolled in Grade 7. Selected primary schools (N=36) were randomly assigned within each of three districts to one of three arms: 1) e-readers, which girls could take home, provided within a safe space group platform plus community engagement activities; 2) safe space groups plus community engagement activities; and 3) control. The intent-to-treat estimates indicate that girls in the e-reader arm scored significantly better on two basic literacy assessments as well as non-verbal reasoning compared with girls in the control arm.
... Thus, the instrument is problematic, as other researchers have also observed in Sub-Saharan Africa more broadly (e.g. Wicherts et al., 2010). ...
... No dose escalation will occur, as 20 mg/kg/ day has efficacy in infants with SCA and is associated with rare myelosuppression. 18,19 Further preliminary data from our feasibility trial,3 indicates that hydroxyurea lowers abnormal TCD measurements ( Figure 1) and prevents strokes. Hydroxyurea will be provided to each participant via the trial pharmacy at no cost for the duration of the trial. ...
Strokes in children with sickle cell anemia (SCA) are associated with significant morbidity and premature death. Primary stroke prevention in children with SCA involves screening for abnormal transcranial Doppler (TCD) velocity coupled with regular blood transfusion therapy for children with abnormal velocities, for at least one year. However, in Africa, where the majority of children with SCA live, regular blood transfusions are not feasible due to inadequate supply of safe blood, cost, and the reluctance of caregivers to accept transfusion therapy for their children. We describe the Primary Prevention of Stroke in Children with Sickle Cell Disease in Nigeria Trial [
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eria (SPRING) trial, NCT02560935], a three-center double-blinded randomized controlled Phase III clinical trial to 1) determine the efficacy of moderate fixed-dose (20 mg/kg/day) versus low fixed-dose (10 mg/kg/day) hydroxyurea therapy for primary stroke prevention; 2) determine the efficacy of moderate fixed-dose hydroxyurea for decreasing the incidence of all cause-hospitalization (pain, acute chest syndrome, infection, other) compared to low fixed-dose hydroxyurea. We will test the primary hypothesis that there will be a 66% relative risk reduction of strokes in children with SCA and abnormal TCD measurements, randomly allocated, for a minimum of three years to receive moderate fixed-dose versus low fixed-dose hydroxyurea (total n = 220). The results of this trial will advance the care of children with SCA in sub-Saharan Africa, while improving research capacity for future studies to prevent strokes in children with SCA.
... Because of its popularity, studies have been conducted in various settings to further investigate the psychometric properties (such as test-retest reliability, convergent validity) of the RAPM, with many of the studies reporting positive results. However, many of these studies only dealt with testlevel statistics such as internal consistency and factor structure of the instrument using raw score measurement theory or classical test theory (CTT) (Bors & Stokes, 1998;Raven, 2000;Wicherts et al., 2010). CTT assumes that a person's score is combination of his or her true ability score, as well as some error in the measurement. ...
The Raven's Advanced Progressive Matrices (RAPM) is considered as one of the most successful measure of general intelligence, particularly the problem-solving and reasoning abilities. However, despite of this, there is no attempt to assess its psychometric properties in Malaysia. To bridge this shortage, the present study assessed the psychometric properties of the 23-item RAPM using a sample of 1,793 Malaysian youth. The assessment involved Rasch Model analysis measurement framework using the following criteria: model assumptions, reliability, construct validity evidence, differential item functioning (DIF), and test targeting. The results showed satisfactory findings from the data for most of the criteria, especially the reliability and validity evidence. Nevertheless, the items in the RAPM was found to lack the ability to target the respondents' general intelligence in the measured scale.
... It is also important to note that the aggregate character of the cognitive measure used in this study (total number of correct answers) reduces the differences found between poor indigenous and non-indigenous children to a question of (quantitative) degree, leaving aside other possible differences (qualitative) with respect to the processes and strategies used to solve the different items of the test (Wicherts, Dolan, Carlson, & van der Maas, 2010). In this sense, the possibility has also been raised that children who solve the test using different information processing strategies can achieve the same level of effectiveness in the resolution of the items, obtaining identical scores that do not imply cognitive equality (Kunda, Soulières, Rozga, & Goel, 2016). ...
Given the correlation between poverty and belonging to certain ethnic groups found by previous studies, the present study intends to apply a statistical technique to analyze the differences in intelligence on the basics of Raven's Coloured Progressive Matrices performance between indigenous children and non-indigenous children from poor rural populations when indigenous children are “treated” as (equated) non-indigenous children in terms of nutrition, maternal education and schooling. This cross-sectional study used the Oaxaca-Blinder decomposition to construct a counterfactual with which to compare both groups, distinguishing between differences due to certain characteristics of the child and those differences that are unexplained by the previous differences. The present study was carried out with a sample N = 1804 of 1460 non-indigenous and 344 indigenous children, aged between 5 and 11 years, from poor rural environments in Mexico who participated and completed a reduced version of the Raven's test of intelligence. The results indicate that, when cognitive performance was equated by age and height of the child, education level of the head of the family, help in school work, and care at home, the observed differences in such performance without being equated was reduced.
... On the one hand, it is consistent with the non-contemporary phenomenon of slave trade. On the other hand, the IQ from the same author has been widely used in scholarly circles to explain contemporary development phenomena, in spite of criticisms such as the under estimation of IQ in African countries (see Kodila-Tedika & Asongu, 2016;Wicherts, Dolan, Carlson, & van der Maas, 2010a, 2010b. Some examples on the wide usage of the IQ, include, its employment to connect and explain other macroeconomic and institutional variables such as: statistical capacity (Kodila-Tedika, Asongu, & Azia-Dimbu, 2017), environmental quality (Salahodjaev, 2016a(Salahodjaev, , 2016b, governance (Kodila-Tedika, 2014;Rindermann, Kodila-Tedika, & Christainsen, 2015), poverty (Kodila-Tedika & Bolito-Losembe, 2014), entrepreneurship (Hafer & Jones, 2015;Salahodjaev, 2016c), economic growth (Jones & Schneider, 2006), financial development (Hafer, 2016;Salahodjaev, 2015a), taxation (Kodila-Tedika & Mutascu, 2014), alcohol consumption (Belasen & Hafer, 2013), economic diversification (Kodila-Tedika & Asongu, 2018), well-being (Hafer, 2016;Nikolaev & Salahodjaev, 2016), gender inequality (Salahodjaev & Azam, 2015) and the informal economy (Salahodjaev, 2015b). ...
One of the most disturbing contemporary episodes in human history that has been decried globally is the recent Libyan experience of slave trade, where migrants captured end-up being sold as slaves. We contribute to the understanding of this phenomenon by investigating the role of cognitive human capital in slave trade. To this end, we use the historic intelligence and slave trade variables respectively, as the independent and outcome variables of interest. Our findings show a negative relationship between slave trade and cognitive human capital. Hence, slave trade is more apparent when cognitive human capital is low. The Ordinary Least Squares findings are robust to the control for outliers, uncertainty about the model and Tobit regressions. We substantiate why from the perspective of massive sensitisation and education, the non-contemporary relationship between cognitive ability and slave trade established in this study has contemporary practical policy relevance in efforts to stem the tide of clandestine travel to Europe through countries in which clandestine migrants are captured and sold as slaves.
... On the one hand, it is consistent with the non-contemporary phenomenon of slave trade. On the other hand, the IQ from the same author has been widely used in scholarly circles to explain contemporary development phenomena, in spite of criticisms such as the under estimation of IQ in African countries (see Kodila-Tedika & Asongu, 2016;Wicherts, Dolan, Carlson, & van der Maas, 2010a, 2010b. Some examples on the wide usage of the IQ, include, its employment to connect and explain other macroeconomic and institutional variables such as: statistical capacity (Kodila-Tedika, Asongu, & Azia-Dimbu, 2017), environmental quality (Salahodjaev, 2016a(Salahodjaev, , 2016b, governance (Kodila-Tedika, 2014;Rindermann, Kodila-Tedika, & Christainsen, 2015), poverty (Kodila-Tedika & Bolito-Losembe, 2014), entrepreneurship (Hafer & Jones, 2015;Salahodjaev, 2016c), economic growth (Jones & Schneider, 2006), financial development (Hafer, 2016;Salahodjaev, 2015a), taxation (Kodila-Tedika & Mutascu, 2014), alcohol consumption (Belasen & Hafer, 2013), economic diversification (Kodila-Tedika & Asongu, 2018), well-being (Hafer, 2016;Nikolaev & Salahodjaev, 2016), gender inequality (Salahodjaev & Azam, 2015) and the informal economy (Salahodjaev, 2015b). ...
One of the most disturbing contemporary episodes in human history that has been decried globally is the recent Libyan experience of slave trade, where migrants captured end-up being sold as slaves. We contribute to the understanding of this phenomenon by investigating the role of cognitive human capital in slave trade. To this end, we use the historic intelligence and slave trade variables respectively, as the independent and outcome variables of interest. Our findings show a negative relationship between slave trade and cognitive human capital. Hence, slave trade is more apparent when cognitive human capital is low. The Ordinary Least Squares findings are robust to the control for outliers, uncertainty about the model and Tobit regressions. We substantiate why from the perspective of massive sensitisation and education, the non-contemporary relationship between cognitive ability and slave trade established in this study has contemporary practical policy relevance in efforts to stem the tide of clandestine travel to Europe through countries in which clandestine migrants are captured and sold as slaves.
... One important issue concerns the accuracy of the IQ statistics generated for Sub-Sahara African countries. Wicherts, et al (2009Wicherts, et al ( , 2010a create an alternative IQ series that focuses on healthy Sub-Saharan populations of normal socio-economic status. This approach yields an average IQ of 80 for this sample, which is significantly higher than that found in the LV data. ...
It has been shown that country-level IQ and aggregated performance by school-age children on international assessment tests in math and science are by-in-large capturing analogous indicators of the cognitive human capital. We expand that analysis by comparing country-level IQ to the World Economic Forum’s Human Capital Index (HCI). This index, comprised of several dozen separate indicators, accounts for inputs and outcomes to measure human capital, across age profiles and gender. Two outcomes are of note. First, there is a positive, significant correlation between IQ and the vast majority of the component indicators in the HCI across all age cohorts. Second, because the HCI’s interpretation of educational attainment extends beyond formal education by including indicators such as on-the-job learning and other work-related skills, our finding that IQ is positively correlated with these measures suggests a deeper connection between national average IQ and the fundamental factors of what constitutes the cognitive side of human capital development.
... 3 Discussion around the use of the three IQ tests is reported elsewhere (Humble, Dixon, & Schagen, 2017) and children were randomly allocated one of the three tests À Ravens Standard Progressive Matrices, Wechsler Abbreviated Scale of Intelligence À Second Edition (WASI-II) or the Naglieri Nonverbal Ability test NNAT-2. The literature around the use of conventional intellectual ability tests with Black Africans living in developing contexts show average IQ scores to be below 70 (Lynn, 2003;Lynn & Vanhanen, 2002, 2006; with systematic literature reviews stating only slightly higher at around 78 (Wicherts, Dolan, & van der Maas, 2009, Wicherts, Dolan, Carlson, & Van der Maas, 2010. Our results therefore do not show any disagreement with the literature. ...
This paper investigates whether pupil’s attainment, attitude and self-confidence are associated with teacher beliefs, experience, school characteristics, background and wealth. Data gathered from 1857 poor children living in Kinondoni, Tanzania included test scores, household data, school and teacher information as well as teacher and peer perceptions. Some results are expected, test scores being significantly and positively correlated, teachers identifying good readers as high ability, and peer and teacher nomination around student ability showing significant levels of concordance. Children from wealthier households are less likely to score higher on tests apart from reading. Teacher experience negatively affects all scores apart from Kiswahili. In general school and teacher factors have a negative affect on children’s self confidence and positive attitude to learning.
... In essence, Wichert et al. have made substantial claims that IQs from Africa based on the Lynn/Vanhanen database are relatively low. According to the authors, the lowers scores should be raised to 76 (Wicherts et al. 2010a) and 80 (Wicherts et al. 2010b). ...
This paper explores the correlates of the intelligence quotient and cognitive ability by focusing on genetic distance to frontier nations. The results based on cross-sectional data from 167 countries suggest that genetic distance to global frontiers has a negative relationship with the employed human capital variables. Countries that are genetically far from leading nations tend to have lower levels of human capital with the negative correlation to the USA frontier averagely higher relative to the UK frontier. The sign is consistent and survives the control of macroeconomic, geographic, institutional and other covariates. Policy implications are discussed.
... They are thus not peer-reviewed. The data used in these analyses are of extremely poor quality (Mackintosh 2007;Wicherts et al. 2010; Wicherts, Dolan and van der Maas 2010a, 2010b). Among many African examples, we may note that the 'national IQ' for Equatorial Guinea was derived from a sample of students attending a school for handicapped children in Spain (Fernández-Ballesteros et al. 1997), that for Ethiopia was derived from a group of displaced orphans in Israel (Kaniel and Fisherman 1991; see also Berhanu 2007) and the testing of South Africans described by Lynn as '[t]he best single study of the Negroid intelligence' was described by the researcher in question (Owen 1989) in the original publication as unsuitable for the derivation of IQ scores. ...
In recent years, the purpose and objectives of ethnoarchaeology have been called into question. In this paper, we propose that ethnoarchaeology might best be considered a form of ‘slow science’ that works to counterbalance ‘big science/fast science’ approaches in archaeology. We consider the interpretative challenges facing archaeology and the risks posed by a shift to fast science approaches that emphasize large-scale, strategic and analytically focused ‘big data’ analyses. We draw on recent literatures that define ‘désexcellence’ and ‘slow science’ approaches, which forefront ethically driven and collaborative research, and suggest that ethnoarchaeology might be well positioned to redefine itself as a form of slow science. Doing so, however, requires redefining ethnoarchaeology’s field objectives and its relations to research subjects.
... Although Raven's Progressive Matrices tests are widely seen as good indicators of g in western samples (Jensen, 1998), it is insufficiently clear whether this applies also to non-western samples that feature in the dozen of studies using MCV on the SPM. For instance, the results of 10 factor analytic studies with the Raven's tests in samples of sub-Saharan African test-takers (Wicherts, Dolan, Carlson, & van der Maas, 2010) suggested that they were relatively weak and not always factorially pure indicators of g. Even in large cognitive test batteries in western samples, the Raven's test certainly not always displayed the highest g loading (Johnson, Bouchard, Krueger, McGue, & Gottesman, 2004). ...
... They attributed the bias on this subtest, called "Learning Names," to the fact that it involved names of fairy tales that might have been less familiar for ethnic minority children, thereby heightening the difficulty level of the test considerably.Even fluid reasoning tests once considered to be culture-free, such as the Raven's Progressive Matrices, are not immune to biasing factors. Notably,Wicherts, Dolan, Carlson, and van der Maas (2010) found that Sub-Saharan African test-takers often obtain lower average scores than Westerners on the various version of the Raven's test. And although reliabilities of the scales were often fairly high, the convergent validity appeared to be lower in sub-Saharan African samples as opposed to studies in the western world. ...
Objective:
Neurocognitive test batteries such as recent editions of the Wechsler's Adult Intelligence Scale (WAIS-III/WAIS-IV) typically use nation-level population-based norms. The question is whether these batteries function in the same manner across different subgroups based on gender, age, educational background, socioeconomic status, ethnicity, mother tongue, or race. Here, the author argues that measurement invariance is a core issue in determining whether population-based norms are valid for different subgroups.
Method:
The author introduces measurement invariance, argues why it is an important topic of study, discusses why invariance might fail in cognitive ability testing, and reviews a dozen studies of invariance of commonly used neurocognitive test batteries.
Results:
In over half of the reviewed studies, IQ batteries were not found to be measurement invariant across groups based on ethnicity, gender, educational background, cohort, or age. Apart from age and cohort, test manuals do not take such lack of invariance into account in computing full-scale IQ scores or normed domain scores.
Conclusions:
Measurement invariance is crucial for valid use of neurocognitive tests in clinical, educational, and professional practice. The appropriateness of population-based norms to particular subgroups should depend also on whether measurement invariance holds with respect to important subgroups.
... However, we cannot realistically predict longer-term trends without making assumptions about the strengths of anticipated Flynn effects in different countries and the resulting changes in average intelligence. For example, the growth trajectories for Sub-Saharan Africa in Tables 5 and 6 are likely to rise above the projection even before 2050 if, as claimed by Wicherts et al (2010), strong Flynn effects are beginning already to raise the average African IQ in the younger generation. Table 1 shows that Flynn effects on IQ tests averaged about 2 or 3 points per decade during the 20 th century, for example in Britain and the United States. ...
This chapter explores the interdependency between economic growth and cognitive human capital, which is also described as cognitive skills or intelligence and is measured either as performance in scholastic achievement tests or IQ. It shows that unlike the mere amount of schooling, intelligence has been a robust predictor of economic growth in the recent past. Plausible mediators of the intelligence effect include greater labor productivity, better institutions, more competent management, lower fertility, and wider time horizons. Based on the observation of secular gains in intelligence that have become known as Flynn effects, a theory of economic growth is developed that is based on the trans-generational reinforcement between rising intelligence and economic, technological and institutional advances. It provides a parsimonious explanation for the sustained nature of economic growth since the Industrial Revolution, and a conceptual framework for more specific theories and hypotheses. The chapter arrives at projections of economic growth for the first half of the 21st century that are based on the empiric relationship between current prosperity, human capital, and economic growth. Longer-term predictions are based on our knowledge of the conditions that are required for continued Flynn effects, and of genetic limits to human cognitive development. The conclusion is that in most countries of Europe and North America, the limits of cognitive growth are being approached or have been reached already by the younger generation. There are ongoing Flynn effects in developing countries today. These countries are now reducing the cognitive gaps separating them from the developed countries, but most of them are expected to reach their cognitive limits before the end of the 21st century. Long-term developments after the end of the Flynn effect will be driven primarily by demographic trends. Without major changes in demographic behavior, intelligence is predicted to eventually decline slowly, ending economic growth in most parts of the world within the next 3 to 4 generations.
Tests of measurement invariance are essential to determining whether individual scores or group averages are comparable across populations. While international comparisons of mean IQ scores are common, tests of measurement invariance for intelligence test batteries (necessary for comparisons to be empirically supported) are rare. In this study, four archival sets of Wechsler test IQ scores from Ghana, Kenya, Pakistan, and Sudan were tested for measurement invariance when compared to the American norm data for the same tests. Results indicate that two datasets – from Ghana and Kenya – demonstrated strict measurement invariance. However, the other two data sets failed to meet the requirements of scalar or strict measurement invariance, which indicates that global IQ scores from these latter data sets cannot be compared to American IQ scores on the same tests. Tests of measurement invariance should be regularly conducted when making comparisons of scores between industrialized and economically developing nations.
Ancestry and country differences in intelligence test scores are a matter of heated discussion. This chapter addresses delicate issues. Even when the data are relatively clear, discussion about their interpretation and meaning easily slips into dispute. We wrote this chapter to shed light and insight instead of lightning and thunder. Our focus is the world because the issues are significant across the globe (Hunt, 2012; Jones, 2016; Rindermann, 2018). To maintain the global focus, we are not detailing data within the United States beyond what is summarized in Box 12.1. As we do throughout this book, we emphasize key research because we agree with James Flynn’s (2018, p. 128) view on this subject: “There will be bad science on both sides of the debate. The only antidote I know for that is to use the scientific method as scrupulously as possible.”
Fluid reasoning (Gf) is a central component of human abilities and has been shown to be statistically indistinguishable from general cognitive ability. However, measuring fluid reasoning is not that easy since the operationalization of the construct itself is not conclusive. This situation is exacerbated if the measurements and comparisons are carried out in groups with different cultural and language abilities. The purpose of this paper is to provide a brief overview of the fluid reasoning construct as well as measurement practices that have been carried out in Indonesia. My review would mention the positioning of fluid reasoning in several intelligence theories, how researchers conceptualize fluid reasoning, how researchers measure fluid reasoning in a multicultural context, and outline critical future directions for test development. In conclusion, I emphasize the importance of using a multi-processes figural fluid reasoning test as a proxy for a culture fair intelligence test that can be used in cross-cultural assessments.
Since Lynn and Vanhanen's book IQ and the Wealth of Nations (2002), many publications have evidenced a relationship between national IQ and national prosperity. The strongest statistical case for this lies in Jones and Schneider's (2006) use of Bayesian model averaging to run thousands of regressions on GDP growth (1960-1996), using different combinations of explanatory variables. This generated a weighted average over many regressions to create estimates robust to the problem of model uncertainty. We replicate and extend Jones and Schneider's work with many new robustness tests, including new variables, different time periods, different priors and different estimates of average national intelligence. We find national IQ to be the "best predictor" of economic growth, with a higher average coefficient and average posterior inclusion probability than all other tested variables (over 67) in every test run. Our best estimates find a one point increase in IQ is associated with a 7.8% increase in GDP per capita, above Jones and Schneider's estimate of 6.1%. We tested the causality of national IQs using three different instrumental variables: cranial capacity, ancestry-adjusted UV radiation, and 19 th-century numeracy scores. We found little evidence for reverse causation, with only ancestry-adjusted UV radiation passing the Wu-Hausman test (p < .05) when the logarithm of GDP per capita in 1960 was used as the only control variable.
Demography was heavily involved in the eugenics movement of the early twentieth century but, along with most other social science disciplines, largely rejected eugenic thinking in the decades after the Second World War. Eugenic ideology never entirely deserted academia, however, and in the twenty-first century, it is re-emerging into mainstream academic discussion. This paper aims, first, to provide a reminder of demography’s early links with eugenics and, second, to raise awareness of this academic resurgence of eugenic ideology. The final aim of the paper is to recommend ways to counter this resurgence: these include more active discussion of demography’s eugenic past, especially when training students; greater emphasis on critical approaches in demography; and greater engagement of demographers (and other social scientists) with biologists and geneticists, in order to ensure that research which combines the biological and social sciences is rigorous.
We argue for the superiority of biologically informed models of human behavior and behavioral variation relative to their purely sociocultural/environmental competitors. It will be shown that opposition to models of the former type emanates largely from scientific ignorance, political motivations, and tacit (but critical) assumptions about the roles of “nature” and “nurture” in human behavior. Chapter 2 surveys a very wide set of empirical and theoretical work that attests to the explanatory power of these biologically informed models. A further matter that this chapter addresses is the substantial collective academic effort to block dissemination of biobehavioral theories of human behavior. We argue that this stems mostly from the substantial overrepresentation of those on the political left in academia, a fact that several researchers have noted.
The purpose of this study is to assess the nexus between intelligence (or human capital) and statistical capacity in developing countries. The line of inquiry is motivated essentially by: (i) the scarce literature devoted to elucidating poor statistics in developing countries and (ii) an evolving stream of literature on knowledge economy. We have established a positive association between intelligence quotient (IQ) and statistical capacity. The relationship is: (i) consistent with the employment of alternative specifications based on varying conditioning information sets and (ii) robust to the control of outliers. Policy implications are discussed.
We assess the correlations between intelligence and financial development in 123 countries using data averages from 2000-2010. Human capital is measured in terms of IQ, cognitive ability & cognitive skills, while financial development is appreciated both from financial intermediary and stock market development perspectives. Short-term financial measures are private and domestic credits whereas long-term financial indicators include: stock market capitalization, stock market value traded and turnover ratio. The following findings are established. (1) With respect to private credit, the positive correlations of IQ and cognitive ability are broadly similar while that of cognitive skills is substantially higher in terms of magnitude. (2) The correlation between intelligence and other financial variables are broadly similar. (3) The underlying findings are broadly confirmed in terms of sign of correlation, though the magnitude of correlation is higher (lower) with the addition of social capital or ethnic fractionalization (institutions or income). (4) When continents are excluded to control for extreme effects, baseline results are confirmed and the following on order of continental importance in financial development is established in increasing magnitude: Africa, Americas, Oceania, Europe & Asia.
A recent line of research in economics and psychology hypothesizes that differences in national average intelligence, proxied by IQ tests, are important drivers of national economic outcomes. Cross-country regressions, while showing a robust IQ-growth relationship, cannot fully test this hypothesis. Thus, recent work explores the micro-foundations of the IQ-productivity relationship. The well-identified psychological relationship between IQ and patience implies higher savings rates and higher folk theorem-driven institutional quality in high average IQ countries. Experiments indicate that intelligence predicts greater pro-social behavior in public goods and prisoner’s dilemma games, supporting the hypothesis that high national average IQ causes higher institutional quality. High average IQ countries also have higher savings intensity by a variety of measures. Other possible IQ-productivity channels are discussed, as are possible environmental causes of differences in national average IQ.
This paper uses propensity score matching to test the robustness of OLS returns to education estimates in Ghana, a country for which other researchers have found low returns to primary school. Matching provides a way to test for common support, which would fail when there are not enough similar non-educated individuals with whom to compare educated individuals. Matching also relaxes the typical linear functional form used in OLS estimates. Common support issues do not seem to bias OLS results, and matching estimates are not statistically different from OLS results, indicating that inflexible functional forms do not bias estimates. These results indicate that, at least in this application, OLS provides reasonable estimates of education returns.
This study was carried out with 1,857 poor children from 17 schools, living in low-income areas of Dar Es Salaam, Tanzania. All children took the ‘Student Multiple Intelligences Profile’ (SMIP) questionnaire as part of a bigger project that gathered data around concepts and beliefs of talent. This paper sets out two aims, first to investigate the structural representation of the self perceived multiple intelligences for this set of children and second to discuss how the best fit model might reflect children’s culture and their school experiences. After carrying out exploratory factor analysis, a four factor first order model was shown to have a good fit. A higher order factor solution was investigated owing to the correlation of two latent constructs. In order to provide some insight into the multiple intelligences construct the relationship between the SMIP items, student test outcomes and attitudes to learning were examined. The item groupings were explored through African cultural beliefs around intelligences indigenous to African communities.
A study was conducted to investigate the intellectual squelae of severe kwashiorkor among Nigeran children of school age. The design for the study had an experimental urban kwashiorkor (index) group and four control groups, namely, a sibling group, a lower class group, an upper class group, and a rural kwashiorkor group. Various psychological tests measuring specific intellectual abilities were administered to all of the subjects taking part in the study. The findings showed that the index group had lower levels of certain types of intellectual skills- specifically the higher cognitive skils- at school age than their siblings, and more so than other controls except their rural counterparts; males showed a tendency to be more affected by severe kwashiorkor with regard to mental development than their female counterpparts; there was no relationship between scores in psychological tests and the ages at which the index cases were admitted into hospital; the upper class was clearly superior in performance of the tests and also in measures of weight and head measurements when compared to all of the other groups; there was no relationship between head circumference and scores in the tests among subjects in the five groups.
Scores on cognitive tasks used in intelligence tests correlate positively with each other, that is, they display a positive manifold of correlations. The positive manifold is often explained by positing a dominant latent variable, the g factor, associated with a single quantitative cognitive or biological process or capacity. In this article, a new explanation of the positive manifold based on a dynamical model is proposed, in which reciprocal causation or mutualism plays a central role. It is shown that the positive manifold emerges purely by positive beneficial interactions between cognitive processes during development. A single underlying g factor plays no role in the model. The model offers explanations of important findings in intelligence research, such as the hierarchical factor structure of intelligence, the low predictability of intelligence from early childhood performance, the integration/differentiation effect, the increase in heritability of g, and the Jensen effect, and is consistent with current explanations of the Flynn effect.
Lynn and Vanhanen test the hypothesis on the causal relationship between the average national intelligence (IQ) and the gap between rich and poor countries by empirical evidence. Based on an extensive survey of national IQ tests, the results of their work challenge the previous theories of economic development and provide a new basis to evaluate the prospects of economic development throughout the world.
They begin by reviewing and evaluating some major previous theories. The concept of intelligence is then described and intelligence quotient (IQ) introduced. Next they show that intelligence is a significant determinant of earnings within nations, and they connect intelligence with various economic and social phenomena. The sociology of intelligence at the level of sub-populations in nations is examined, and the independent (national IQ) and dependent (various measures of per capita income and economic growth rates) variables are defined and described. They then provide empirical analyses starting from the 81 countries for which direct evidence of national IQs is available; the analysis is then extended to the world group of 185 countries. The hypothesis is tested by the methods of correlation and regression analyses. The results of statistical analyses support the hypothesis strongly. The results of the analyses and various means to reduce the gap between rich and poor countries are discussed. A provocative analysis that all scholars, students, and researchers involved with economic development need to confront.
Four groups of new immigrant students from Ethiopia in Israel (N = 46) participated. They were tested using the Raven's Standard Progressive Matrices and received cognitive intervention in the form of the Learning Potential Assessment Device procedure. The intervention included teaching problem-solving strategies using material similar but not identical to Raven's Matrices. A profile of students' responses was estimated. The results suggest that the new immigrant students initially had a cognitive profile different from that of native Israeli students. The intervention appeared to be effective not only in improving the absolute score on the Matrices but also in changing the students' cognitive profile.
Raven's Standard Matrices were administered three times to students in their sixth year of schooling in France and in the Congo. When self-paced, 63 French and 88 Congolese students progressed moderately from Tests 1 to 2 and made no progress from Sessions 2 to 3. When timed, the French and Congolese subjects progressed rapidly from Sessions 1 to 2 (with a sharper progression by the French subjects) but only the Congolese progressed from Sessions 2 to 3. A simple retest procedure emerges as a poor candidate for correcting biases based on imbalances in familiarity with problem situations and the test situation in cross-cultural comparisons. It is suggested that dynamic evaluation procedures could reduce these biases.
There are signs that the debate over racial and gender differences in intelligence is about to begin again. In this article we will be concerned primarily with racial differences but will make remarks about gender differences where applicable. Previously there have been bitter arguments over whether or not races exist, over whether it is either important or proper to study racial and gender differences in intelligence, and over the conclusions that have been drawn about environmental and genetic causes as determinants of these differences. We argue that races do, indeed, exist and that studying differences in cognitive competence between groups is a reasonable thing to do. We also point out that past research on both racial and gender differences in intelligence has been marked by methodological errors and overgeneralizations by researchers on all sides of the issue. We propose ten principles of design, analysis, and reporting that ought to be considered carefully when doing or evaluating research in this area.
© 2007 Association for Psychological Science.
Over the last two decades, a number of psychometric researchers have claimed that very substantial differences in intelligence exist among modern human racial groups, as these groups are traditionally defined. According to these researchers, African populations suffer severe cognitive deficits when compared to other modern humans. Philippe Rushton, particularly, places these claimed mental deficits in an evolutionary context, advancing environmental explanations for such deficits and asserting that such cognitive differences existed prehistorically as well. Such substantial cognitive differences should be evident in human behavioural patterns, and thus in the archaeological record. Archaeological data can thus be used to test these claims about human evolutionary development and modern human cognitive difference. Examination of the archaeological record does not support the claims made by these researchers. This suggests that regional differences in IQ test score results should not be ascribed to variations in human evolutionary development.
There is a continuing need for formalised assessment procedures that can be adapted for group comparisons across diverse cultures to facilitate school and occupational placement, as well as to evaluate the effectiveness of nutritional, education, and medical intervention programs. This study used a direct translation of the Kaufman Assessment Battery for Children (K‐ABC) to evaluate 130 Zairian primary school children. The distinction between Sequential Processing and Simultaneous Processing abilities on the K‐ABC was generally found to be valid in this sample. The K‐ABC also discriminated effectively among grade levels, differences in health and family environment indicators, and tribal membership. Reasonable test‐retest correlations for the K‐ABC global scales were also found with a subsample of the children. The Zairian children's K‐ABC scores, particularly for the Simultaneous subtests, were markedly lower than the American normative sample. Education and experiential factors inherent in the sub‐Sahara environment may put these children at a significant cultural disadvantage in terms of the skills required for successful completion of K‐ABC items.
The social-emotional state and cognitive development was compared between a group of 74 4-7-year-old Eritrean orphans and refugee children living in families. Both groups had been exposed to the chronic stresses of war and drought and the orphans had, in addition, lost both parents to the violence of war, and were living in an overcrowded orphanage- Contrary to expectations, there were relatively few clinically significant differences between comparison groups. The orphans showed more behavioral symptoms of emotional distress, but performed at a more advanced level on cognitive and language performance measures. The findings suggest that when group care is child-centered, it can under some circumstances be a viable solution for unaccompanied children in countries where adoption and foster care are not realistic alternatives.
The gains of scores on standardized intelligence tests (i.e., Flynn effect) have been the subject of extensive debate concerning their nature, causes, and implications. The aim of the present study is to investigate whether five intelligence tests are measurement invariant with respect to cohort. Measurement invariance implies that gains over the years can be attributed to increases in the latent variables that the tests purport to measure. The studies reported contain original data of Dutch Wechsler Adult Intelligence Scale (WAIS) gains from 1967 to 1999, Dutch Differential Aptitude Test (DAT) gains from 1984 to 1995, gains on a Dutch children intelligence test (RAKIT) from 1982 to 1993, and reanalyses of results from Must, Must, and Raudik [Intelligence 167 (2003) 1–11] and Teasdale and Owen [Intelligence 28 (2000) 115–120]. The results of multigroup confirmatory factor analyses clearly indicate that measurement invariance with respect to cohorts is untenable. Uniform measurement bias is observed in some, but not all subtests. The implications of these findings are discussed.
Professor James Flynn is one of the most creative and influential psychologists in the field of intelligence. The ‘Flynn Effect’ refers to the massive increase in IQ test scores over the course of the twentieth century and the term was coined to recognize Professor Flynn’s central role in measuring and analyzing these gains. For over twenty years, psychologists have struggled to understand the implications of IQ gains. Do they mean that each generation is more intelligent than the last? Do they suggest how each of us can enhance our own intelligence? Professor Flynn is finally ready to give his own views. He asks what intelligence really is and gives a surprising and illuminating answer. This book bridges the gulf that separates our minds from those of our ancestors a century ago. It is a fascinating and unique book that makes an important contribution to our understanding of human intelligence.
This book penetrates the thicket of controversy, ideology and prejudice surrounding the measurement of intelligence to provide a clear non-mathematical analysis of it. The testing of intelligence has a long and controversial history and whether intelligence exists and can be measured still remains unresolved. The debate about it has centered on the "nurture versus nature" controversy and especially on alleged racial differences and the heritability of intelligence. © David J. Bartholomew 2004 and Cambridge University Press, 2009.
A longitudinal study of 375 boys and 380 girls just beginning the seventh grade was started in November 1977. The sample, whose mean age was 13.06 yr. ( SD = 1.66), was representative of seventh grade students in Oyo State, one of the 19 states in Nigeria. Health, height, onset of menarche in girls, intellectual maturity, and certain social factors were most closely associated with self-concepts.
This is a review of the relationship between schooling, IQ, and the cognitive processes presumed to underpin IQ. The data suggest that much of the causal pathway between IQ and schooling points in the direction of the importance of the quantity of schooling one attains (highest grade successfully completed). Schooling fosters the development of cognitive processes that underpin performance on most IQ tests. In western nations, schooling conveys this influence on IQ and cognition through practices that appear unrelated to systematic variation in quality of schools. If correct, this could have implications for the meaning one attaches to IQ in screening and prediction as well as for efforts to influence the development of IQ through changes in schooling practices.
Data from 14 nations reveal IQ gains ranging from 5 to 25 points in a single generation. Some of the largest gains occur on culturally reduced tests and tests of fluid intelligence. The Norwegian data show that a nation can make significant gains on a culturally reduced test while suffering losses on other tests. The Dutch data prove the existence of unknown environmental factors so potent that they account for 15 of the 20 points gained. The hypothesis that best fits the results is that IQ tests do not measure intelligence but rather a correlate with a weak causal link to intelligence. This hypothesis can also explain differential trends on various mental tests, such as the combination of IQ gains and Scholastic Aptitude Test losses in the United States.
This book is about differences in intellectual capacity among people and groups and what those differences mean for America's future.(preface) The major purpose of this book] is to reveal the dramatic transformation that is currently in process in American society---a process that has created a new kind of class structure led by a "cognitive elite," itself a result of concentration and self-selection in those social pools well endowed with cognitive abilities. Herrnstein and Murray explore] the ways that low intelligence, independent of social, economic, or ethnic background, lies at the root of many of our social problems. The authors also demonstrate the truth of another taboo fact: that intelligence levels differ among ethnic groups. (PsycINFO Database Record (c) 2012 APA, all rights reserved)(jacket)
The investigation compared social maturity levels in rural and urban children with mental retardation (between 40 and 70 IQ points). The magnitude of discrepancy between the subjects' IQ and their social quotients (SQ) was examined using an SQ:IQ ratio. Rural subjects had a significantly higher SQ:IQ ratio than urban ones, and age was also positively correlated with this ratio. No significant gender difference was evident. The rural children's higher social maturity relative to their IQ must be considered in the context of their life experiences, which are in various ways different to that of urban children. From an early age, rural children are involved in household and community responsibilities, such as fetching water, firewood, herding cattle, and other practices that are not as common among urban children. The findings lend support to the idea that even in disadvantaged communities, given appropriate opportunities, children with mental retardation do have the capacity to enhance their social competence, possibly more so than those in less challenging environments.
A software version of the Austin Maze together with the Halstead-Reitan Category Test and Raven's Standard Progressive Matrices were administered to 30 students at the University of Venda, South Africa. For the entire sample, the average number of trials taken to reach criterion (that is, three consecutive error-free trials) on the Austin Maze was 19. The performance of male subjects was generally better than that of females. No significant correlations were found between performance on the Austin Maze and scores on the other psychometric tests. This is seen as implying that, for this group of subjects, the Austin Maze measures a different construct, as documented in the literature. The complexity of a contextual interpretation of the subjects poorer performance on the measures is discussed.
The Raven's Coloured Progressive Matrices (CPM) test is internationally recognised as a culture-fair test of non-verbal intelligence, designed for use with children between the ages of 51/4 and 111/2 years. The Raven's CPM is used extensively across a wide variety of settings in South Africa. However, more appropriate local normative data has yet to be established. This pilot study seeks to establish normative data for this instrument for a population of isiXhosa-speaking primary school children in a peri-urban area of the Eastern Cape, South Africa. The booklet version of the test was used in group format and according to an alternative method of test administration (using isiXhosa instructions) developed by Vass (1992). The final normative sample consisted of 197 male and 182 female isiXhosa-speaking children in Grades 2 to 7 (n = 379). This study presents a set of local norms for the age group, 6 to 11 years. In addition, it was found that older children (>11 years of age) who have not yet reached certain educational levels, have also not reached the plateau, as anticipated, in their performance on this test. In addition, therefore, is a set of 'older norms' also presented and the issues related to grade versus age norms are debated. The tendency for this normative sample to perform lower than their Western counterparts on this test was also noted and debated. The tendency for males to outperform females was also recorded and it was found that this is in line with previous research on similar populations. The study concludes that there is an urgent need for more appropriate South African normative data for this test; and that, when assessing African children from disadvantaged backgrounds, further research into the effects of cultural and socio-economic factors and gender on non-verbal analogical reasoning tasks (and performance on this test in particular) is required.
An experiment was conducted to examine the effects of metacognitive instruction on mathematics achievement and attitude towards mathematics of low mathematics achievers at a middle school in the North‐West Province of South Africa. Forty standard (std) 7 pupils were identified whose non‐verbal general ability and previous mathematics achievements were significantly lower than those of other std 7 pupils. These subjects were randomly assigned to an experimental group and a control group. Metacognitive strategies in solving mathematical problems related to four mathematics topics were individually taught to the members of the experimental group, while the pupils in the control group were taught the four mathematics topics through the conventional method of teaching mathematics. The comparisons of pretest and posttest measures of general ability, metacognitive awareness, attitude towards mathematics, and mathematics achievement revealed that the posttest scores of all the four variables for the experimental group were significantly higher than those for the control group.
In this chapter the definition, detection, and explanation of item bias is discussed. Item bias is generally defined as conditional dependence; within the framework of item response theory the general definition implies that the item characteristic curves of two groups do not coincide. For detecting biased items, statistical tests and indices based on item response theory have been proposed. Several methods have been compared using empirical or simulated data. Methods combining information on the regression of item responses on latent trait or observed test score and information on the latent trait or observed test score distribution appear to do a good job in detecting biased items. Next to these general methods, specific methods are available that might perform better under specific assumptions and conditions. For explaining detected item bias, four strategies are described: (1) qualitative, (2) correlational, (3) quasi-experimental, and (4) experimental research.
This article examines the suitability of the Raven Standard Progressive Matrices Test (SPM) for groups of white, coloured, Indian and black pupils in Standard 7 in South Africa. The four groups show very little difference in test reliabilities, the rank order of item difficulties, item discrimination values, and the loadings of items on the first principal component. Consequently, from a psychometric point of view, the SPM is not culturally biased. However, the test is not culture or ethnic ‘blind’ either. This is revealed by discriminant analysis which shows that the largest proportion of the black and white testees follow the general pattern of their own group. (This tendency is far less evident in the coloured and Indian groups.) The groups also show large mean test score differences, especially between black and white pupils where the differences is nearly 3 SD units. Regarding the nature of these differences, it was found that items which discriminate best within the groups were also the items that showed the largest differences between the groups.It was concluded that, despite the similar properties of the SPM for the various groups, the test is nevertheless unsuitable—on account of the large mean differences—for use as a common test with common norms for black and white pupils in Std 7. In a multicultural society like South Africa, this finding poses serious problems for psychologists who are concerned with the establishment of common tests for all.
In order to measure the effect of schooling on cognitive skills, the performance of 230 6 to 13 yr old Hausa schoolchildren on a variety of congenitive tasks was compared to that of 175 like aged Hausa children who did not attend school. Schooled children had sufficiently higher scores on most tests throughout the age range tested, but since these differences were present in the youngest children (who had very little schooling) and did not increase among the older children, the effect of schooling did not appear to be cumulative with time. Alternate explanations are discussed.
Person-fit methods based on classical test theory-and item response theory (IRT), and methods investigating particular types of response behavior on tests, are examined. Similarities and differences among person-fit methods and their advantages and disadvantages are discussed. Sound person-fit methods have been derived for the Rasch model. For other IRT models, the empirical and theoretical distributions differ for most person-fit statistics when used with short and moderate length tests. The detection rate of person-fit statistics depends on the type of misfitting item-score patterns, test length, and trait levels. The usefulness of person-fit statistics for improving measurement depends on the application.
Statistical methods developed over the last decade for detecting measurement bias in psycho logical and educational tests are reviewed. Earlier methods for assessing measurement bias generally have been replaced by more sophisticated statistical techniques, such as the Mantel-Haenszel procedure, the standardization approach, logistic regression models, and item response theory approaches. The review employs a conceptual framework that distin guishes methods of detecting measurement bias based on either observed or unobserved conditional invariance models. Although progress has been made in the development of statistical methods for detecting measurement bias, issues related to the choice of matching variable, the nonuniform nature of measurement bias, the suitability of cur rent approaches for new and emerging perform ance assessment methods, and insights into the causes of measurement bias remain elusive. Clearly, psychometric solutions to the problems of measurement bias will further understanding of the more central issue of construct validity. The con tinuing development of statistical methods for detecting and understanding the causes of mea surement bias will continue to be an important scientific challenge.