Using more complex items than those commonly employed within the information-processing approach, but still easier than those used in intelligence tests, this study analyzed how the association between processing speed and accuracy level changes as the difficulty of the items increases. The study involved measuring cognitive ability using Raven's…

We recently proposed the Creative Reasoning Test (CRT), a test for reasoning in ill-defined problem spaces. The test asks children who first performed the Standard Progressive Matrices test (SPM) to next generate an SPM-style test item themselves. The item is scored based on different aspects of its complexity. Here we introduce a method to…

Child prodigies are unusual for their early and exceptional adoption of what are traditionally thought of as adult abilities. As part of an effort to better understand the underpinnings of these extraordinary individuals' talent, the researcher examined the cognitive and developmental profiles of eight child prodigies by taking their developmental…

Sex differences on the Attention Test (AC), the Raven's Standard Progressive Matrices (SPM), and the Brazilian Cognitive Battery (BPR5), were investigated using four large samples (total N=6780), residing in the states of Minas Gerais and Sao Paulo. The majority of samples used, which were obtained from educational settings, could be considered a…

Research has consistently revealed that average IQ scores vary significantly across macro-level units, such as states and nations. The reason for this variation in IQ, however, has remained at the center of much controversy. One of the more provocative explanations is that IQ across macro-level units is the result of genetic differences, but…

This is a study of secular score gains in South Africa. The findings are based on representative samples from datasets utilized in norm studies of popular mainstream intelligence batteries such as the WAIS as well as widely used test batteries which were locally developed and normed in South Africa. Flynn effects were computed in three ways.…

The Flynn effect is the rise in IQ scores across the last eighty or more years documented in the general distribution of both industrialized and developing nations primarily on tests that require problem solving and non-verbal reasoning. However, whether the effect extends to the right tail (i.e., the top 5% of ability) remains unknown. The…

Childhood intelligence (age 11) and occupational social status at midlife (age 46 to 51) was associated with marital status and reproduction in a sample from the Aberdeen Children of the 1950s cohort study (N = 9614). Male and female divorcees had lower childhood intelligence test scores than their married counterparts, but no meaningful…

The general differentiation hypothesis states that the strength of the correlations among a set of IQ subtests varies with a given variable. Instances of the general differentiation hypothesis that have been considered in the literature include age and ability differentiation. Traditionally, the differentiation effect is attributed to the varying…

This study investigates the comparability of IQ scores. Three cohorts (1933/36, 1997/98, 2006) of Estonian students (N = 2173) are compared using the Estonian National Intelligence Test. After 72 years the secular rise of the IQ test scores is 0.79 SD. The mean 0.16 SD increase in the last 8 years suggests a rapid increase of the Flynn Effect (FE)…

The ranking of Wechsler subtests in terms of their "g" loadings is equivalent to ranking them in terms of the cognitive complexity of the tasks measured. Lower performing groups do not always fall behind higher performing groups the more complex the task. But that is the general rule, no matter whether the cause of the lower performance…

The acknowledged high relationship between working memory and intelligence suggests common underlying cognitive mechanisms and, perhaps, shared biological substrates. If this is the case, improvement in working memory by repeated exposure to challenging span tasks might be reflected in increased intelligence scores. Here we report a study in which…

Item responses to Digit Span and Letter-Number Sequencing were analyzed to develop a better-refined model of the two working memory tasks using the finite mixture (FM) modeling method. Models with ordinal latent traits were found to better account for the independent sources of the variability in the tasks than those with continuous traits, and…

Research into sex differences in general intelligence, g, has resulted in two opposite views. In the first view, a g-difference is nonexistent, while in the second view, g is associated with a male advantage. Past research using Multi-Group Covariance and Mean Structure Analysis (MG-CMSA) found no sex difference in g. This failure raised the…

Individuals scoring high in fluid intelligence tasks generally perform very efficiently in problem solving tasks and analogical reasoning tasks presumably because they are able to select the task-relevant information very quickly and focus on a limited set of task-relevant cognitive operations. Moreover, individuals with high fluid intelligence…