The transient enhancement of performance on spatial tasks in standardized tests after exposure to the first movement "allegro con spirito" of the Mozart sonata for two pianos in D major (KV 448) is referred to as the Mozart effect since its first observation by Rauscher, Shaw, and Ky (1993). These findings turned out to be amazingly hard to…

Individual differences in general mental ability ("g") have important implications across multiple disciplines. Research suggests that the variance in "g" may be due to a general fitness factor. If this is the case, a relationship should exist between "g" and other reliable indicators of fitness. Some empirical results indicate a relationship…

Meta-analyses are presented of sex differences in (1) the (mental) arithmetic subtest of the Wechsler intelligence tests for children and adolescents (the WISC and WPPSI tests), showing that boys obtained a mean advantage of 0.11d; (2) the (mental) arithmetic subtest of the Wechsler intelligence tests for adults (the WAIS tests) showing a mean…

There is scientific and popular dispute about whether there are sex differences in cognitive abilities and whether they are relevant to the proportions of men and women who attain high-level achievements, such as Nobel Prizes. A recent meta-analysis (Lynn, R., and Irwing, P. (2004). Sex differences on the progressive matrices: a meta-analysis.…

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…

A meta-analysis is presented of 57 studies of sex differences in general population samples on the Standard and Advanced Progressive Matrices (SPM and APM, respectively). Results showed that there is no difference among children aged 6-14 years, but that males obtain higher means from the age of 15 through to old age. Among adults, the male…

Two meta-analyses, one with 27,973 subjects in 31 studies and one with 34,262 subjects in 141 studies, found that tests of short-term memory are valid predictors of job and training performance and that racial differences are smaller than is usual on cognitive tests. (SLD)

A meta-analysis of research on the relationship between inspection time (IT) and IQ was performed. The analysis was designed to determine whether a non-zero relationship between IT and IQ exists, estimate the size of this relationship, and test whether IT is ontogenetically related to "g" (intelligence). (TJH)