Although a negative relationship between fertility and education has been described consistently in most countries of the world, less is known about the relationship between intelligence and reproductive outcomes. Also the paths through which intelligence influences reproductive outcomes are uncertain. The present study uses the NLSY79 to analyze…

This paper reviews the studies of socioeconomic and ethnic and racial differences in intelligence carried out in Russia/USSR during the late 1920s and early 1930s. In these studies the IQs of social classes and of ethnic minorities were tested. These included Tatars (a Caucasoid people), Chuvash and Altai (mixed Caucasoid-Mongoloid peoples), Evenk…

African-Americans and Whites were asked to solve problems typical of those administered on standard tests of intelligence. Half of the problems were solvable on the basis of information generally available to either race and/or on the basis of information newly learned. Such knowledge did not vary with race. Other problems were only solvable on…

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…

The current study examines the views of experts in the science of mental abilities about the primacy and uniqueness of "g" and the social implications of ability testing, and compares their responses to the views of a group of non-expert psychologists. Results indicate expert consensus that "g" is an important, non-trivial determinant (or at least…

Cranial capacities are calculated from external head measurements reported for 40 samples (tens of thousands of subjects) from a 1990 review of ergonomically important body measurements compiled by the International Labour Office. The correlation between brain size and intelligence for groups and individuals is discussed. (SLD)

The impetus for our study was the contention of both Lynn [Lynn, R. (1991) "Race differences in intelligence: A global perspective." "Mankind Quarterly," 31, 255-296] and Rushton [Rushton, J. P. (1995). "Race, evolution and behavior: A life history perspective." New Brunswick, NJ: "Transaction"; Rushton, J.…

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…

Calculation of cranial capacities for the means from 4 Mongoloid and 20 Caucasoid samples (raw data from 57,378 individuals in 1978) found larger brain size for Mongoloids, a finding discussed in evolutionary terms. The conclusion is disputed by L. Willerman but supported by J. P. Rushton. (SLD)

A large number of national and geographic population samples were used to test the hypothesis that the variation in mean values of skin color in the diverse populations are consistently correlated with the mean measured or estimated IQs of the various groups, as are some other physical variables, known as an ecological correlation. Straightforward…

Michael Levin argues that data from the study are consistent with a black/white IQ difference that is significantly genetic. Richard Lynn maintains that adoption by middle-class, white families has no effect on intelligence. Waldman, Weinberg, and Scarr respond to these criticisms and support the original conclusions. (SLD)

R. Herrnstein and C. Murray, in "The Bell Curve," stated six propositions concerning a "g" factor of intelligence. These propositions are found to be reasonably well supported in the scientific literature. These conclusions can be reached whether or not one accepts Herrnstein and Murray's claims about the social significance of…

Data used to support Spearman's hypothesis have been incorrectly and inconsistently reported and do not support the claim that African-American-white differences in intelligence are not environmental in origin. Deaf children should not be considered a single population with respect to linguistic deprivation. (SLD)

Genetic influence was estimated on Wechsler Intelligence Scale for Children subtests from inbreeding depression scores calculated on cousin marriages in Japan (n=1,854 children) and correlated with American Black-White racial differences. The genetic contribution of racial differences in cognitive performance may be more robust than was previously…