Creativity is likely to be related to intelligence, though the nature of this relationship remains largely unresolved and few studies have examined creativity in the context of measures traditionally related to intelligence. Like intelligence, creativity has often been studied as a static trait or as subject to change over long durations through…

In this study, we tested the parasite-stress hypothesis for the distribution of intelligence among the USA states: the hypothesis proposes that intelligence emerges from a developmental trade-off between maximizing brain vs. immune function. From this we predicted that among the USA states where infectious disease stress was high, average…

The level of self-employment varies significantly among immigrants from different countries of origin. The objective of this research is to examine the relationship between home-country national intelligence and self-employment rates among first generation immigrants in Norway. Empirical secondary data on self-employment among immigrants from 117…

We have previously demonstrated that training on a dual n-back task results in improvements in fluid intelligence ("Gf") as measured by matrix reasoning tasks. Here, we explored the underlying mechanisms of this transfer effect in two studies, and we evaluated the transfer potential of a single n-back task. In the first study, we demonstrated that…

Social, or "generalized" trust is often characterised as the "attitudinal dimension" of social capital. It has been posited as key to a host of normatively desirable outcomes at the societal and individual levels. Yet the origins of individual variation in trust remain something of a mystery and continue to be a source of…

In complex three-dimensional mental rotation tasks males have been reported to score up to one standard deviation higher than females. However, this effect size estimate could be compromised by the presence of gender bias at the item level, which calls the validity of purely quantitative performance comparisons into question. We hypothesized that…

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…

This paper examines the distribution of national IQ in geographical space. When the heritability of IQ and its dependence on eco-social factors are considered from a global perspective, they suggest that the IQs of neighboring countries should be similar. Using previously published IQ data for 113 nations (Lynn, R., & Vanhanen, T., (2006). IQ and…

Derived changes in genes associated with primary microcephaly (MCPH) have been suggested to be "currently sweeping to fixation" i.e., increasing in frequency in most populations, with the likely outcome that the derived allele will completely displace the ancestral allele over time. Possible causes for this sweep include effects on human reasoning…

Spearman's hypothesis states that racial differences in IQ between Blacks (B) and Whites (W) are due primarily to differences in the "g" factor. This hypothesis is often confirmed, but it is less certain whether it generalizes to other races. We therefore tested its cross-racial generality by comparing American subjects of European…

Presents simple and direct demonstrations showing why basic measurement principles require that biases in data created by measurement error be removed. Refutes common objections to the correction for these biases. Also describes substantive psychological processes responsible for some types of measurement error. (SLD)

Although most discussions today start from the assumption that the secular rise in IQ must be environmental in origin, three reasons warrant giving the genetic phenomenon heterosis a closer look as a potential cause. First, it easily accounts for both the high heritability and low shared environmental effects seen in IQ, findings that are…

IQ scores provide the best general predictor of success in education, job training, and work. However, there are many ways in which IQ scores can be increased, for instance by means of retesting or participation in learning potential training programs. What is the nature of these score gains? Jensen [Jensen, A. R. (1998a). "The g factor: The…

Gardner [Gardner, H. (2006-this issue). On failing to grasp the core of MI theory: A response to Visser et al. "Intelligence"] criticized some aspects of our empirical examination [Visser, B. A., Ashton, M. C., & Vernon, P. A. (2006-this issue). Beyond "g": Putting multiple intelligences theory to the test. "Intelligence"] of his "Theory of…

The possibility that Spearman's Hypothesis is a statistical artifact is assessed in a review of six studies of deaf children's intelligence. Results clearly refute the proposal that the positive relationship between Black-White differences and "g" loadings is a statistical artifact and provide evidence of divergent validity for…