Lynn (2010a, 2010b) argued that individuals from south Italy have a lower IQ than individuals from north Italy, and that these differences in IQ are at the basis of north-south gap in income, education, infant mortality, stature, and literacy. In the present paper, we discuss several theoretical and methodological aspects which we regard as flaws…

The present study investigated the unique contribution of learning approaches to academic performance, also taking gender differences into account. The participant sample consisted of 476 school pupils (53% girls and 47% boys) from two upper secondary schools in Sweden who completed two self-reported measures related to personality and learning…

Wicherts, Dolan, Carlson & van der Maas (WDCM) (2010) contend that the average IQ in sub-Saharan Africa is about 76 in relation to a British mean of 100 and sd of 15. This result is achieved by including many studies of unrepresentative elite samples. Studies of acceptably representative samples indicate a sub-Saharan Africa IQ of…

This retrospective study examined L1 achievement, intelligence, L2 aptitude, and L2 proficiency profiles of 208 students completing two years of high school L2 courses. A cluster analysis was performed to determine whether distinct cognitive and achievement profiles of more and less successful L2 learners would emerge. The results of…

In recent years, models of giftedness have incorporated personal and social variables which influence IQ, rather than taking IQ into account exclusively. Among the various options presented in this context, authors have proposed dynamic assessment techniques as a method for revealing the potential capacity in different groups, independently of the…

The present study investigated cognitive abilities in children with difficulties in mathematics only (n = 48, M = 8 years and 5 months), combined mathematical and language difficulty (n = 27, M = 8 years and 1 month) and controls (n = 783, M = 7 years and 11 months). Cognitive abilities were measured with seven subtests, tapping visual perception,…

The investment theory of Cattell supposes an influence of fluid on crystallized intelligence. The development of fluid intelligence largely depends on biological factors, of crystallized intelligence on fluid intelligence and environmental stimulation. To test this theory two contrasting samples representing a broad ability range were chosen, a…

In his comment on our literature review of data on the performance of sub-Saharan Africans on Raven's Progressive Matrices, Lynn (this issue) criticized our selection of samples of primary and secondary school students. On the basis of the samples he deemed representative, Lynn concluded that the average IQ of sub-Saharan Africans stands at 67…

We examined the cross-lagged relations between children's task-avoidant behavior and their performance in reading and spelling in Chinese. Eighty Grade 2 and 103 Grade 4 Mandarin-speaking Taiwanese children were assessed on measures of nonverbal IQ, task value, reading accuracy, fluency, and spelling. A year later, the children were reassessed on…

Individual differences in mathematics performance may stem from domain-general factors like working memory and intelligence. Parietal and frontal brain areas have been implicated in number processing, but the influence of such cognitive factors on brain activity during mathematics processing is not known. The relationship between brain mechanisms…

The aim of the present study was to investigate the contribution of working memory and verbal ability (measured by vocabulary) to mathematical skills in children. A sample of 206 seven- and eight-year-olds was administered tests of these cognitive skills. A different pattern emerged that was dependent on both the memory task and the math skill. In…

The role of IQ in individual differences in real-life problem solving and strategies use was explored. Repeated trials of learning and recall of information from a map were analyzed with high IQ and average IQ Korean students. IQ correlated with the selection and use of strategies in recall. However, the performance and strategic behaviors of…

It is argued that it is unnecessary to propose that Confucian values explain the high achievements in math and science of the North East Asian peoples, and that these can be satisfactorily and more parsimoniously be explained by their high IQs.

In this paper we assess the presence of assortative mating, gene-environment interaction and the heritability of intelligence in childhood using a twin family design with twins, their siblings and parents from 112 families. We evaluate two competing hypotheses about the cause of assortative mating in intelligence: social homogamy and phenotypic…

Studies on the well-being of gifted adults are rare, and the available studies are often limited by methodological shortcomings. In a longitudinal project 101 intellectually gifted adults (mean IQ = 136) were compared to 91 adults of average intelligence (mean IQ = 103). Subjective well-being was operationalized by positive and negative…