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…

Charles Spearman originally suggested in 1927 that the varying magnitudes of the mean differences between whites and blacks in standardized scores on a variety of mental tests are directly related to the size of the tests' loadings on g, the general factor common to all complex tests of mental ability. Several independent large-scale studies…

Methodological tools such as analysis of variance designs can reflect bias. Difficulties in the interpretation of cross-cultural differences can be avoided only if the researcher considers all external variables which account for the variance. No variance should be left to be explained in terms of culture. (VM)

This paper examines the question of the hereditary nature of intelligence and the validity of some of the statistical procedures which have been used in measuring the degree of hereditability. The author feels that proof of the question lacks sufficient scientific rigor for the support of any conclusion, particulary for a question of such…

This author reviews published data and presents new data relevant to the Spearman hypothesis concerning racial differences on cognitive tests. He concludes that across-the-board difference between SES groups occurs primarily on the general factor, and that there are major determinants of race differences independent of the general factor.…

This paper critically examines the portions of Arthur Jensen's books, "Genetics and Education" and "Educability and Group Differences," that concern Barbara Burks' 1928 study of adoptive families. Jensen cites the low correlations of children's IQs with measures of home environment from Burks' study as evidence that environment…