A systematic literature review of the average IQ of sub-Saharan Africans

On the basis of several reviews of the literature, Lynn [Lynn, R., (2006). Race differences in intelligence: An evolutionary analysis. Augusta, GA: Washington Summit Publishers.] and Lynn and Vanhanen [Lynn, R., & Vanhanen, T., (2006). IQ and global inequality. Augusta, GA: Washington Summit Publishers.] concluded that the average IQ of the Black population of sub-Saharan Africa lies below 70. In this paper, the authors systematically review published empirical data on the performance of Africans on the following IQ tests: Draw-A-Man (DAM) test, Kaufman-Assessment Battery for Children (K-ABC), the Wechsler scales (WAIS & WISC), and several other IQ tests (but not the Raven's tests). Inclusion and exclusion criteria are explicitly discussed. Results show that average IQ of Africans on these tests is approximately 82 when compared to UK norms. We provide estimates of the average IQ per country and estimates on the basis of alternative inclusion criteria. Our estimate of average IQ converges with the finding that national IQs of sub-Saharan African countries as predicted from several international studies of student achievement are around 82. It is suggested that this estimate should be considered in light of the Flynn Effect. It is concluded that more psychometric studies are needed to address the issue of measurement bias of western IQ tests for Africans.     

IQ and the wealth of states

In IQ and the Wealth of Nations (2002), Lynn and Vanhanen estimate the mean IQs of 185 nations and demonstrate that national IQs strongly correlate with the macroeconomic performance of the nations, explaining about half of the variance in GDP per capita. I seek to replicate Lynn and Vanhanen's results across states within the United States. I first estimate “state IQs” from the SAT data, and show that the state IQs correlate moderately with the economic performance of the states, explaining about a quarter of the variance in GSP (gross state product) per capita.     

Richard Lynn’s contributions to personality and intelligence

An evaluation is presented of Lynn’s work on national differences in personality, race differences in intelligence, national IQs & economic development, correlates of national IQs, the Flynn effect, sex differences, eugenics and dysgenics, race differences in psychopathic personality, and intelligence of the Jews.     

IQ differences between the north and south of Italy: A reply to Beraldo and Cornoldi,Belacchi, Giofre,Martini, and Tressoldi

Beraldo (2010) and Cornoldi, Belacchi, Giofre, Martini, and Tressoldi (2010) (CBGMT) have eight criticisms of my paper (Lynn, 2010) claiming that the large north–south differences in per capita income in Italy are attributable to differences in the average levels of intelligence in the populations. CBGMT give results for seven data sets for IQs in the north and south of Italy. All of these show that IQs are higher than in the north than in the south, although the differences are not as great as those I calculated. Other criticisms to the effect that the PISA tests are not measures of intelligence are refuted. The results of two further studies are given that confirm that IQs in the north of Italy are approximately 10 IQ points higher than in south.     

National intelligence and suicide rate across Europe: an alternative test using educational attainment data

National mean scores on a historical knowledge test (taken as a proxy for intelligence), stemming from representative samples of male (and female) 9th-grade school students from 26 European countries in a 1999 report by Wilberg and Lynn, were significantly positively associated with the national male (and female) suicide rates, independent of the general quality-of-living conditions in these countries. This finding replicates previous evidence from cross-national studies (by Lester and by Voracek), of a correspondence of higher national IQ to higher suicide rates, with an alternative measure of national IQ that is independent of the national IQ estimates recently published by Lynn and Vanhanen which have been used in prior studies.     

Cross-national social ecology of intelligence and suicide prevalence: integration, refinement, and update of studies

This study integrates, refines, and updates previous findings pertaining to positive ecologic (population-level) associations between intelligence and suicide prevalence across nations by using corrected and revised national IQ estimates and, further, a quality-of-human-conditions index, both recently published by Lynn and Vanhanen. Across a global 85-nation sample of sex-specific total suicide rates and a Eurasian 48-nation sample of sex-specific elderly suicide rates, these were positively associated with updated national IQ estimates. The associations were stronger for the general population than for elderly persons, independent of the quality of human conditions, and notedly stronger in exponential fitting of suicide rates with national IQ than in linear fitting, thereby indicating that shifts or differences in national IQ correspond to proportional, not absolute, changes in suicide rates. Implications of these findings and the question of generalizability of such associations to the individual level are discussed.     

Recent data for majority and racial minority differences in intelligence of 5 year olds in the United Kingdom

Data are presented from the UK Millennium Cohort Study for a sample of 14,860 5 year old British children giving the IQs of whites and racial minorities. Africans, Indians, Pakistanis and Bangladeshis obtained lower IQs than whites, while the IQ of the Chinese was higher. These group differences in IQ were consistent with the differences in educational attainments and earnings.     

Are cognitive differences between countries diminishing? Evidence from TIMSS and PISA

Cognitive ability differences between countries can be large, with average IQs ranging from approximately 70 in sub-Saharan Africa to 105 in the countries of north-east Asia. A likely reason for the great magnitude of these differences is the Flynn effect, which massively raised average IQs in economically advanced countries during the 20th century. The present study tests the prediction that international IQ differences are diminishing again because substantial Flynn effects are now under way in the less developed “low-IQ countries” while intelligence is stagnating in the economically advanced “high-IQ countries.” The hypothesis is examined with two periodically administered scholastic assessment programs. TIMSS has tested 8th-grade students periodically between 1995 and 2011 in mathematics and science, and PISA has administered tests of mathematics, science and reading between 2000 and 2009. In both TIMSS and PISA, low-scoring countries tend to show a rising trend relative to higher-scoring countries. Despite the short time series of only 9 and 16 years, the results indicate that differences between high-scoring and low-scoring countries are diminishing on these scholastic achievement tests. The results support the prediction that through a combination of substantial Flynn effects in low-scoring countries and diminished (or even negative) Flynn effects in high-scoring countries, cognitive differences between countries are getting smaller on a worldwide scale.     

A comparative study of intellectual abilities of Japanese and American children on the Columbia Mental Maturity Scale (CMMS)

Lynn has published a series of papers on cross-cultural comparison of IQs. In three of his papers, Lynn indicated that the Japanese performed higher on IQ tests, and analyzed this from a socio-ecological point of view. This paper presents a comparison of intellectual abilities of Japanese and American children on the Columbia Mental Maturity Scale (CMMS).     

Myth and reality: A response to Lynn on the determinants of Italy's North-South imbalances

In his article “In Italy, North-South differences in IQ predict differences in income, education, infant mortality, stature, and literacy,” Richard Lynn claims to have found the reason causing the divergence between the Northern and the Southern regions of Italy. This article identifies the four main hypotheses formulated in his paper and presents significant evidence against each one of them. We claim that the evidence presented by the author is not sufficient to say that the IQ of Southern Italians is lower than the one of Northern Italians; that his analysis does not prove that there is any causal link between what he defines as IQ and any of the variables mentioned; that there is no evidence that the alleged differences in IQ are persistent in time and, therefore, attributable to genetic factors.     

Genetic and environmental transactions underlying educational attainment

This report used a population-representative longitudinal twin study with two birth cohorts to explore the association between intelligence and education by understanding how genetic and environmental influences on intelligence moderate genetic and environmental influences on school grades and educational attainment. Nonshared environmental influences on grades were strong when IQ was low, but decreased across the range of IQ. Shared environmental influences common to age 24 educational attainment and age 17 IQ were strong when IQ was low, but genetic influences common to IQ and education were strong when IQ was high. These results suggest that the causal mechanisms linking educational variables with intelligence differ for people with different levels of intelligence.     

Incongruence Between Native and Test Administration Languages: Towards Equal Opportunity in International Literacy Assessment

Previous research has primarily addressed the effects of language on the Program for International Student Assessment (PISA) mathematics and science assessments. More recent research has focused on the effects of language on PISA reading comprehension and literacy assessments on student populations in specific Organization for Economic Cooperation and Development (OECD) and non-OECD countries. Recognizing calls to highlight the impact of language on student PISA reading performance across countries, the purpose of this study was to examine the effect of home languages versus test languages on PISA reading literacy across OECD and non-OECD economies, while considering other factors. The results of Ordinary Least Squares regression showed that about half of the economies demonstrated a positive and significant effect of students' language status on their reading performance. This finding is consistent with observations in the parallel analysis of PISA 2009 data, suggesting that students' performance on reading literacy assessment was higher when they were tested in their home language. Our findings highlight the importance of the role of context, the need for new approaches to test translation, and the potential similarities in language status for youth from OECD and non-OECD countries that have implications for interpreting their PISA reading literacy assessments.     

学校教育资源对学生数学素养预测效应的跨文化比较

采用国际学生评价项目PISA2006的数据,使用多水平线性模型方法,比较中国香港、日本、芬兰和美国四个国家（地区）的学校教育资源与学生数学素养成绩的关系。结果发现,在控制学生背景变量的情况下,学校教育资源对学生数学素养成绩的影响在四个国家（地区）之间存在一定的文化差异：学校大小、生师比对中国香港学生数学素养成绩有显著的正向预测作用;学校大小、班级大小、学校类型、有硕士研究生学历的教师比例对日本学生数学素养成绩有显著的正向预测作用,用于教学的计算机比例对日本学生数学素养成绩有显著的反向预测作用;学校教育资源对芬兰学生数学素养成绩没有显著的预测作用;学校类型对美国学生数学素养成绩具有显著的反向预测作用。     

Determinants of educational achievement at 16+: Intelligence,personality, home background and school

The classical path model linking home background with IQ and school type to educational attainment is extended by the inclusion of the EPQ and new questionnaires measuring Status Aspiration and Work Ethic. In a study of approx. 700 adolescents it was shown that Psychoticism and Status Aspiration are significant variables in the prediction of educational achievement. The most important determinant of educational attainment was found to be intelligence.     

Expanding the g-nexus: Further evidence regarding the relations among national IQ, religiosity and national health outcomes

The current study seeks to better understand how religiosity and health are positioned within the g-nexus. Specifically, the degree to which differences in average IQ across nations is associated with differences in national religiosity (i.e., belief rate) and national health statistics independent of differences in national wealth is examined. Consistent with expectations, results show that, independent of national wealth and belief rate, IQ has a positive influence on national health as indicated by fertility rate, infant mortality rate, maternal mortality rate, and deaths due to HIV/AIDS, and life expectancy. Additionally, as hypothesized, IQ and belief rate interacted to influence reproductive health (i.e., fertility rate, infant- and maternal mortality). Specifically, high IQ acts as a buffer against the negative effects of belief rate; when IQ is high belief rate has no effect, but when IQ is low belief rate has a strong negative effect. The pattern of findings from this study, combined with previous research, serve to confirm that general cognitive ability (i.e., the g-factor) is an important and central node within a larger nexus of psychological and social variables. Theoretical and epidemiological implications are discussed.     

Pygmalion in the genes? On the potentially negative impacts of polygenic scores for educational attainment

Social Psychology of Education - Polygenic scores for educational attainment and related variables, such as IQ and “mathematical ability” are now readily available via...     

Factor Structure and Construct Validity of the Temporal Experience of Pleasure Scales

Feelings of pleasure felt in the moment of goal attainment (consummatory pleasure) are thought to be dissociable from feelings of desire connected with the motivated approach of goals (anticipatory pleasure). The Temporal Experience of Pleasure Scales (TEPS; Gard, Gard, Kring, & John, 2006) was developed to assess individual differences in these distinct processes. Recently, an independent evaluation of the psychometric characteristics of a Chinese-translated TEPS suggested a more complex factor structure (Chan et al., 2012). This study aimed to reexamine the factor structure and convergent and divergent validity of the TEPS in two previously unexamined multiethnic samples. University students in the United Kingdom (N = 294) completed the TEPS and university students in Australia (N = 295) completed the TEPS as well as a battery of conceptually related questionnaires. A confirmatory factor analysis of Gard et al.'s (2006) 2-factor model produced inadequate fit, which model-modification indexes suggested might be due to item cross-loadings. This issue was examined further using an exploratory factor analysis, which revealed a clear 2-factor solution despite cross-loadings among some items. Finally, mixed evidence for convergent–divergent validity was obtained, in terms of relationships between the TEPS and measures of anhedonia, approach-motivation, and positive emotion.     

Relationship of the Wechsler pre-school and primary scale of intelligence and the Stanford-Binet (L-M) in lower class children

Using 72 lower class children, concurrent validity of the WPPSI was studied employing Form L-M of the Stanford-Binet as the criterion. Correlations between SB and WPPSI were moderately high (.86 for FS, .81 for VS, .73 for PS), but the WPPSI appeared a somewhat more difficult test for the sample employed. Mean SB IQ (94.61) was higher than the mean FS (90.71), VS (89.38) and PS (93.68) IQs; it exceeded WPPSI IQ in 72% of all cases. On the WPPSI, PS IQ was significantly greater than either VS or FS IQs. Amont the WPPSI subtests, Vocabulary was significantly lower than all other subtests and Comprehension lower than Picture Completion, Mazes, and Block Design. The only significant sexual difference favored females on Similarities. For subjects whose FS IQ was below the group median IQ, relationships among each of the WPPSI scales and subtests were lower than for those subjects who scored above the median. This was particularly true for the Vocabulary, Animal House, and Picture Completion subtests.     

Beyond IQ: A latent state-trait analysis of general intelligence, dynamic decision making, and implicit learning

The present study investigated cognitive performance measures beyond IQ. In particular, we investigated the psychometric properties of dynamic decision making variables and implicit learning variables and their relation with general intelligence and professional success. N = 173 employees from different companies and occupational groups completed two standard intelligence tests, two dynamic decision making tasks, and two implicit learning tasks at two measurement occasions each. We used structural equation models to test latent state-trait measurement models and the relation between constructs. The results suggest that dynamic decision making and implicit learning are substantially related with general intelligence. Furthermore, general intelligence is the best predictor for income, social status, and educational attainment. Dynamic decision making can predict supervisor ratings even beyond general intelligence.