We investigated time-related patterns in levels of cognitive performance during the period from 1970 to 1993 based on data from Swedish draft boards. The conscripts, including more than a million 18-19-year old men, had taken one of two versions of the Swedish enlistment battery (SEB67; 1970-1979 or SEB80; 1980-1993), each composed of four…

Jaeggi and her colleagues claimed that they were able to improve fluid intelligence by training working memory. Subjects who trained their working memory on a dual n-back task for a period of time showed significant improvements in working memory span tasks and fluid intelligence tests such as the Raven's Progressive Matrices and the Bochumer…

Three prominent theories of intelligence, the Cattell-Horn-Carroll (CHC), extended fluid-crystallized (Gf-Gc) and verbal-perceptual-image rotation (VPR) theories, provide differing descriptions of the structure of intelligence (McGrew, 2009; Horn & Blankson, 2005; Johnson & Bouchard, 2005b). To compare these theories, models representing them were…

The nature of contextual facilitation effects for items derived from Raven's Progressive Matrices was investigated in two experiments. For these, the original matrices were modified, creating either abstract versions with high element salience, or versions which comprised realistic entities set in familiar contexts. In order to replicate and…

Measures of broad fluid abilities including verbal, quantitative, and figural reasoning are commonly used in the K-12 school context for a variety of purposes. However, differentiation of these domains is difficult for young children (grades K-2) who lack basic linguistic and mathematical literacy. This study examined the latent factor structure…

For this study, European WAIS III performance subtest norms were compared to the original US norms. When European WAIS III raw scores were scored using US norms, the resulting perceptual organization index (POI) means were significantly higher than the processing speed index (PSI) means. The POI/PSI difference is roughly 5-10 points for the German…

Criticisms advanced by Felice and Giugliano (2011) of the thesis that IQs in Italy are higher in the north than in the south are answered and new data confirming the thesis are given from the PISA 2009 study and for math and reading abilities in the recent INVALSI study. New genetic data are given showing higher frequency of blond hair the…

Marked gender differences in three-dimensional mental rotation have been broadly reported in the literature in the last few decades. Various theoretical models and accounts were used to explain the observed differences. Within the framework of linking item design features of mental rotation tasks to cognitive component processes associated with…

Watson's Jeopardy victory raises the question of the similarity of artificial intelligence and human intelligence. Those of us who study human intelligence issue a challenge to the artificial intelligence community. We will construct a unique battery of tests for any computer that would provide an actual IQ score for the computer. This is the same…

The interpretation of retest scores is problematic because they are potentially affected by measurement and predictive bias, which impact construct validity, and because their size differs as a function of various factors. This paper investigates the construct stability of scores on a figural matrices test and models retest effects at the level of…

In 1977 Draw-a-Person test was administered to fifth grade school children in a city and its surrounding rural villages in Turkey. In 2010, more than thirty years later, the test was administered again to a corresponding group of fifth grade children in the same locations. It is rare that we get scores from the "same" population over a…

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)…

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…

This paper compares different theoretical models of the structure of intelligence, based on the analysis of data obtained in a series of measured abilities corresponding to the Spectrum assessment activities (Gardner, Feldman & Krechevsky, 1998) in a sample of 393 children enrolled in kindergarten and first grade. The data were analyzed using…

The relationship between measures of IQ and standardized school achievement tests is well established at around r~0.5 when the two are measured in close proximity. The current paper examined the stability of this correlation when comparing elementary school achievement (grades 3-8) and midlife IQ. Iowa Adoption Study participants who had…