In the present study, speeded tasks with differing assumed difficulties of the trials are regarded as a special class of simple cognitive tasks. Exploratory latent growth modeling with data-driven shape of a growth curve and nonlinear structured latent curve modeling with predetermined monotonically increasing functions were used to analyze…

The aim of the study was to investigate the relationship between the Flynn effect and the effects of age differences between siblings on the intelligence difference between them. In Norway, the secular trends in intelligence-test score means vary both in magnitude and direction. We identified three periods: one period where the mean intelligence…

Lynn (2010) suggests that differences in average intelligence explain many of the differences observed across the Italian regions. This paper puts forward a methodological critique to his study, coupling it with an empirical test showing that Lynn's analysis is not sufficiently robust to support its conclusions. (Contains 2 tables.)

Intelligence is an important indicator of physical, mental and social well-being. In old age, intelligence is also associated with a higher quality of life and better health. Heritability studies have shown that there are strong genetic influences, yet unknown, on intelligence, including in old age. Other approaches may be useful to investigate…

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 present study provides a preliminary empirical test of [Chamorro-Premuzic, T., & Furnham, A. (2004). A possible model to understand the personality-intelligence interface. "British Journal of Psychology," 95, 249-264], [Chamorro-Premuzic, T., & Furnham, A. (2006a). Intellectual competence and the intelligent personality: A…

A three-stage model for the evolution of theories of intelligence is proposed and applied to understanding the evolution of correlationally based and experimentally based theories of intelligence. In stage one, alternative conceptions compete. In subsequent stages, alternative conceptions, which combine elements of prior approaches, emerge and…

Because no single characteristic defines intelligence, there can be no adequate process-based definition of intelligence. In principle, a combination of many empirically derived measures into a single index, as in a Binet test, would be appropriate. In practice, many of the relevant characteristics are simply impossible to measure. (Author/RD)

The Ravens Standard Progressive Matrices Test was administered to 48 subjects who then performed a card-sorting task under single- and competing-task conditions. Hick's Law and the Roth-Jensen procedure were used in task development. Complexity should have a more central role in speed of processing models of intelligence than ability to divide…

Taylor (1980) claims to show that the similarity in IQ between monozygotic twins reared apart found in prior studies is due to similarity in their environments. A reanalysis using Taylor's classification of environments but an alternative IQ measure shows that his findings do not constructively replicate. (Author/RD)

This editorial suggests how the approaches of differential psychology and information processing psychology should be combined to study intelligence. Methods reviewed include factor analysis, componential analysis, and computer simulation. Guidelines for the specification of subtheories of intelligence, as well as future theories and methods for…

Two studies examined differences in intellectual ability associated with masculinity and femininity in high school and college students. Available from: Ablex Publishing Corporation, 355 Chestnut Street, Norwood, New Jersey 07648. (CL)

The question of how to integrate developmental (Piagetian) and psychometric conceptions and assessments of intelligence is considered. A solution which incorporates the contributions of each position--intelligence as forms and as traits--is offered. Premises and objectives of each tradition are reviewed and compared. Overlaps make synthesis…

Data from the General Social Survey (GSS) collected in the years 1990-1996 are examined for the relationship between fertility and intelligence as measured by vocabulary. The results show that the relation between fertility and intelligence has been consistently negative for successive birth cohorts from to 1900 to 1979, indicating the presence of…

Persons representing the extremes of intelligence cannot be included in the same study unless they are approximately equated on mental age, in which case the relative performances of the extreme groups can provide useful information about the nature of intelligence. (Author/RD)