The dangers of unsystematic selection methods and the representativeness of 46 samples of African test-takers

Abstract

In this rejoinder, we criticize Lynn and Meisenberg's (this issue) methods to estimate the average IQ (in terms of British norms after correction of the Flynn Effect) of the Black population of sub-Saharan Africa. We argue that their review of the literature is unsystematic, as it involves the inconsistent use of rules to determine the representativeness and hence selection of samples. Employing independent raters, we determined of each sample whether it was (1) considered representative by the original authors, (2) drawn randomly, (3) based on an explicated stratification scheme, (4) composed of healthy test-takers, and (5) considered by the original authors as normal in terms of Socio-Economic Status (SES). We show that the use of these alternative inclusion criteria would not have affected our results. We found that Lynn and Meisenberg's assessment of the samples' representativeness is not associated with any of the objective sampling characteristics, but rather with the average IQ in the sample. This suggests that Lynn and Meisenberg excluded samples of Africans who average IQs above 75 because they deemed these samples unrepresentative on the basis of the samples' relatively high IQs. We conclude that Lynn and Meisenberg's unsystematic methods are questionable and their results untrustworthy.